It was very hard to write code generators for; and it didn't have much reasons to succeed in the first place (It was made by Intel, so what?). The architecture allowed Itanium to be relatively simple while providing tools for the compiler to eek out performance from it. I've heard some JITs gave worse perfomance than interpreters on Itanium because gcc optimized interpreter better; that's a no-go if a processor requires that level of optimizations. Processor architecture as a lot to do with programming. Closed again. for AMD64), sharing some compiler know-how. When you could really properly fill it, which often involved either PGO or hand-coding, it did great - but a lot of the time, performance from compilers was really just uninspiring. Get a clue if you got the bucks to run an itanium, why criple it with the sins of the past. However the first gens focussed transistor count on other performance schemes since the compiler handled a lot of the hard stuff. Memory is getting vague... Itanium had some great ideas that would need great compiler support. While i've always felt that the argument of "the compiler was the one and only problem" was overblown - there were legitimate microarchitectural issues that really did I2 no favors for general-purpose code - it was not especially fun to generate code for compared to the narrower, higher-clocked OoO machines of the day. Well, the only reason really is HP-UX. POWER would be an option, but IBM is a competitor and Compaq already has a working relationship with Intel. Aleksandr, as an aside, dataflow architectures have all dependencies explicit. Each one wasn't a big deal, all together were. As Robert Munn pointed out -- it was the lack of backward compatibility that killed the Itanium ( and many other "new" technologies). The second key difference is that out-of-order processors determine these schedules dynamically (i.e., each dynamic instruction is scheduled independently; the VLIW compiler operates on static instructions). Applies to: Windows Server 2008 R2 Service Pack 1 Windows Server 2008 R2 Datacenter Windows Server 2008 R2 Enterprise Windows Server 2008 R2 Standard Windows Server 2008 R2 Foundation Windows Server 2008 R2 for Itanium-Based Systems Windows 7 Service Pack 1 Windows 7 Ultimate Windows 7 Enterprise Windows 7 Professional Windows 7 Home Premium Windows 7 Home … Several issues: a) add something to the instruction set, and you need to support it even if it makes no sense anymore (e.g., delayed branch slots). like x86. DSP. There were also branch and cache prefetch hints that could really only be used intelligently by an assembly programmer or using profile-guided optimization, not generally with a traditional compiler. rev 2020.12.2.38097, The best answers are voted up and rise to the top, Software Engineering Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us, Really-low-level IRs (that are actually specified beyond being internal to one compiler, and intended to be compiled onto specific hardware rather than interpreted portably) are a more recent invention AFAIK. Why did the Intel Itanium microprocessors fail? @Nubok: Not correct - there were two mechanisms, PAE & PSE-36, to gain access to memory >4GB on 32-bit machines and none involved segment descriptors at all. You are perhaps underestimating the cost at which current processor achieve their performance. Software Engineering Stack Exchange is a question and answer site for professionals, academics, and students working within the systems development life cycle. Working with WSUS, I sometimes find myself declining the exact same type of updates each month after Patch Tuesday. The Itanium 9500 series processor, codenamed Poulson, is the follow-on processor to Tukwila and was released on November 8, 2012. Leaving optimization to the compiler was a good idea. If the platform had lived, the CPUs would have become more complex, and eventually become threaded, out of order etc. Early chips were atrocious. The chips were expensive, difficult to manufacture, and years behind schedule. CPU hardware has the advantage of dynamic scheduling, and I don't think there is an example of statically scheduled processor which is competitive on pure performance for single thread with OOO. It's commonly stated that Intel's Itanium 64-bit processor architecture failed because the revolutionary EPIC instruction set was very difficult to write a good compiler for, which meant a lack of good developer tools for IA64, which meant a lack of developers creating programs for the architecture, and so no one wanted to use hardware without much software for it, and so the platform failed, and all for the want of … Many have tried all have failed. Itanium never achieved the economy of scale that x86 & x64 was able to leverage to lower R&D costs per unit because of issue 5. As a result, the Itanium failed both Intel and HP’s goals for it. I think Itanium still has its market - high end systems and HP blade servers. That's fine; the compiler already has that information, so it is straightforward for the compiler to comply. It was only difficult relative to the alternatives. However, most general-purpose software must make plenty of random memory accesses. But why was the compiler stuff such a difficult technical problem? What a truly pathetic business model! How to move a servo quickly and without delay function. Itanium was announced in 1997 (as Merced at the time) but it didn't ship until 2000 which is what eventually doomed it, really. Can I (a US citizen) travel from Puerto Rico to Miami with just a copy of my passport? Intel's Itanium, once destined to replace x86 processors in PCs, hits end of line Intel has released its Itanium 9700 chip, but that also means the end for the processor family. So you have to know how and why it works at least a little. Itanium never achieved the necessary price/performance advantage necessary to overcome "platform inertia" because it was frequently delayed to compensate for issues 1-4. Working with WSUS, I sometimes find myself declining the exact same type of updates each month after Patch Tuesday. Room: Moderated Discussions. this is really programming related - just because it mentions hardware does not make it server fault material. How do people recognise the frequency of a played note? In other words, it externalizes a secondary responsibility, while still failing to cope with the primary responsibility. What came first, the compiler, or the source? Is there any reason why Intel didn't specify a "simple Itanium bytecode" language, and provide a tool that converts this bytecode into optimized EPIC code, leveraging their expertise as the folks who designed the system in the first place? IBM has had many failed projects – the Stretch system from the 1950s and the Future Systems follow-on in the 1970s are but two. But they won't admit how miserably it failed. It also isn’t hard to understand why Compaq’s chose Itanium. MIPS, Alpha, PA-RISC -- gone. It's its place in time and market forces. They started a visionary research project using personnel and IP from two notable VLIW companies in the 80s (Cydrome and Multiflow -- the Multiflow Trace is btw the negative answer posed in the title, it was a successful VLIW compiler), this was the Precision Architecture Wide-Word. David W. Hess (dwhess@banishedsouls.org) on 7/6/09 wrote: >My observations at the time were that the 386 performance increase over the 286 @supercat: I'm not talking about a hypothetical VM, but about a hypothetical IR that would be compiled the rest of the way by an Intel code generator. If multiple instructions are ready to go and they don't compete for resources, they go together in the same cycle. Update the question so it's on-topic for Stack Overflow. Erm. How do I place the Clock arrows inside this clock face? Solamente algunos miles de los Itanium se vendieron, debido a la disponibilidad limitada causada por baja producción, relativamente pobre rendimiento y alto coste. IBM has had many failed projects – the Stretch system from the 1950s and the Future Systems follow-on in the 1970s are but two. Itanium failed because VLIW for today's workloads is simply an awful idea. x86-64 smashed that barrier and opened up higher power computing to everyone. So why would one buy an Itanium now? Does "Ich mag dich" only apply to friendship? Who doesn't love being #1? In reality, prefetching is only profitable if you are performing streaming operations (reading memory in a sequential, or highly predictable manner). Itanium - Why it failed? I accidentally used "touch .." , is there a way to safely delete this document? In a CPU like the Itanium or the SPARC with 200+ registers, this can be rather slow. For scientific computation, where you get at least a few dozens of instructions per basic block, VLIW probably works fine. The Itanium chip might have given Intel much grief, but it is through difficult and sometimes failed projects that companies learn. At each change a large percentage of existing software continued to run. [closed], early Itanium CPUs execute up to 2 VLIW bundles per clock cycle, 6 instructions, informit.com/articles/article.aspx?p=1193856, en.wikipedia.org/wiki/File:Top500.procfamily.png. Why?? (That said, if your code makes frequent access to some localized memory areas, caching will help.). It was slow, but it was there. What is the output of a fingerprint scanner? Donald Knuth, a widely respected computer scientist, said in a 2008 interview that "the "Itanium" approach [was] supposed to be so terrific—until it turned out that the wished-for compilers were basically impossible to write." We understand those are the last of the Itanium chips available, launched in 2017 as four and eight-core parts, meaning by Fall 2021, it's all over for the doomed family. The compilers became quite good at it, especially when using PGO profiling (I worked at HP and HP's compiler tended to outperform Intel's). How can one plan structures and fortifications in advance to help regaining control over their city walls? As you look to deploy these feature updates in your organization, I want to tell you about some changes we are making to the way Windows Server Update Services … Why Itanium Failed To Be Adopted Widely. I was told that there are lots of partial reasons that all accumulated into a non-viable product in the market. What IBM said was that with PowerPC, you could compile bytecode quickly and the CPU would make it fast. What do I do to get my nine-year old boy off books with pictures and onto books with text content? - "/g/ - Technology" is 4chan's imageboard for discussing computer hardware and software, programming, and general technology. The engineering part was actually pretty successful. Is it considered offensive to address one's seniors by name in the US? Simple. (*) By "cope with", it is necessary to achieve reasonably good execution performance (in other words, "cost-competitive"), which necessitates not letting the CPU fall idle for tens to hundreds of cycles ever so often. Re:Why Itanium Failed. In my opinion it is very "programming-related", because whatever we program gets executed by that processor-thingie inside the machines. Sad. It was a commercial failure. Is it worth getting a mortgage with early repayment or an offset mortgage? As I mentioned above, part of that dynamic information is due to non-deterministic memory latency, therefore it cannot be predicted to any degree of accuracy by compilers. No one knows if its hardware or software, but it just isn't do-able. Choose a random function for analysis. Why do new language versions typically use an early compiler version for the bootstrap compiler? Intel are probably the. IPF didn't make it easy to generate great code, and it was unforgiving when code wasn't great. Not on Itanium. 80x86 has supported 36-bit physical addressing (or a limit of "not quite 64 GiB of RAM") since the introduction of PAE and PSE36 in about 1995. If you look at ISA successes, it's often not the technical side that rolls the dice. At same generation and fab technology, it would have been running faster and capped all the same but a bit higher, with maybe other doors to open to push Moore's law. It was hard to make a single binary that performed optimally on multiple generations of Itanium processors. Intel® Itanium® Processor product listing with links to detailed product features and specifications. The issue with EPIC is that it can use only the parallelism that a compiler can find, and extracting that parallelism is hard. With Itanium due in 1999 (and full of hype at this point), SGI canned the "Beast" project and decided to migrate. OOO is more effective than the other possibilities, but it is surely not efficient. February 24, 2020 seasoned_geek. 11 years later he's still basically right: per-thread performance is still very important for most non-server software, and something that CPU vendors focus on because many cores is no substitute. Windows on Itanium has a WoW layer to run x86 applications. Sort of the best out of both approaches. Complexity of compilers? The Intel ITANIUM. The first Itanium chip was delayed to 2001 and failed to impress most potential customers who stuck to their x86, Power and SPARC chips. Maybe they thought that IA64 would be so much better than anything else that they could move the entire market. Despite all attempts taken, DEC failed to make prices on their Alpha processors, ... OpenVMS 8.4 for Alpha and Itanium was released in June of 2010. DeepMind just announced a breakthrough in protein folding, what are the consequences? It was slower than PA-RISC2, slower than Pentium 3, not quite compatible plus very expensive and power hungry. Later, further fuelling the Osborne effect, in the beginning of 2002 after Itanium sales off to a slow start one could read analysts saying "One problem is that McKinley...is expensive to manufacture. How is Intel killing off all the competition, using a single product line, anything but the greatest microprocessor victory of all time? Lactic fermentation related question: Is there a relationship between pH, salinity, fermentation magic, and heat? In my opinion, failure to cope with memory latency is the sole cause of death of EPIC architecture. A lot of stuff can be done static that otherwise is inefficient in hardware. I guess that their management underestimated the efforts needed to make a compiler. rev 2020.12.2.38097, Stack Overflow works best with JavaScript enabled, Where developers & technologists share private knowledge with coworkers, Programming & related technical career opportunities, Recruit tech talent & build your employer brand, Reach developers & technologists worldwide. @delnan's point about low-level IR is smack on, I just don't think it would have made a difference. @rwong, I made a TLDR of what I consider my main points. why did itanium fail? It could have been some POWERPC64 (but it probably wasn't because of patent issues, because of Microsoft demands at that time, etc...). (*) If we could ever make NOP do useful work ... Modern CPUs try to cope with the same using dynamic information - by concurrently tracking the progress of each instruction as they circulate through the pipelines. Itanium failed because it sucked. AMD's move was so successful that Intel (and Via) were essentially forced to adopt the x86-64 architecture. Having all dependencies explicit, however, restricts your programming (no regular memory). Does your organization need a developer evangelist? most software companies would have bitten the bullet and made the effort. What killed Itanium was shipment delays that opened the door for AMD64 to step in before software vendors commited to migrate to IA64 for 64 bit apps. Is this purely down to marketing? The big problem is that when it asked me to run root.sh on both node 1 & 2 it returns Checking to see if Oracle CRS stack is already configured Setting the permissions on OCR backup directory Setting up NS directories Failed to upgrade Oracle Cluster Registry configuration. It wasn't x86 compatible. But why was the compiler stuff such a difficult technical problem? What was an issue is the hyper-threading implementation by swapping stacks during memory IO was too slow (to empty and reload the pipeline) until Montecito etc. At the time of release software developers were waiting for a decent marketshare before writing software for it and PC buyers were waiting for a decent amount of software before buying. It also means yields are lower ... Not until you get into Madison and Deerfield in 2003 do you start talking about volume." For future processor architectures the strategy you describe might be good now that the JVM has demonstrated that a JIT can achieve general-purpose code performance that's competitive with native code, but I don't think that was clear when IA64 was being developed. In response to answer by Basile Starynkevitch. Itanium designed rested on the philosophy of very wide instruction level parallelism to scale performance of a processor when clock frequency limit is imposed due to thermal constraints. Intel y HP reconocen que Itanium no es competitivo y lo reemplazan por el Itanium 2 un año antes de lo planeado, en 2002. Itanium came out in 1997. That's not to say they didn't exist at all, but I think the idea was not at all obvious or well-known for quite a while. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. So there must be a better explanation... No. [failed verification] According to Intel, it skips the 45 nm process technology and uses a 32 nm process technology. Schedule the following script to decline all Itanium updates. There were specific reasons why Intel did what they did, unfortunately I cannot dig up any definitive resources to provide an answer. Why is a third body needed in the recombination of two hydrogen atoms? Itanium failed to make significant inroads against IA-32 or RISC, and suffered further following the arrival of x86-64 systems which offered greater compatibility with older x86 applications. In a 2009 article on the history of the processor — "How the Itanium Killed the Computer Industry" — journalist John C. Dvorak reported "This continues to be one of the great fiascos of the last 50 years". site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. It merely says that the burden of indicating data dependency now falls on the compiler. Those instructions are executed speculatively anyway (based on branch prediction, primarily). Note that the coping strategy employed by EPIC (mentioned in the Wikipedia article linked above) does not actually solve the issue. “The operation was a success, although the patient died,” goes the old surgeon’s joke. Itanium's VLIW instruction bundles offered speculative execution to avoid failed branch prediction costs, but the practice of executing calculations that were discarded most of the time ate into the CPU power budget, which was becoming an increasingly limited resource at the time Itanium was released. They were the market power at the time. The real reason for this epic failure was the phenomenon called "too much invested to quit" (also see the Dollar Auction) with a side of Osborne effect. In hindsight, the failure of Itanium (and the continued pouring of R&D effort into a failure, despite obvious evidence) is an example of organizational failure, and deserves to be studied in depth. The IPF platform bet on the compiler and tools, and it was the first archiecture to expose an extremely complete and powerful Performance Monitoring Unit (PMU) design, that was later ported back to Intel x86. DeepMind just announced a breakthrough in protein folding, what are the consequences. Reordering of memory and arithmetic instructions by modern compilers is the evidence that it has no problem identifying operations that are independently and thus concurrently executable. It is not "... (whatever) is hard", it is that EPIC is unsuitable for any platform that has to cope with high dynamism in latency. What are multiplexed and non-multiplexed address pins? In that respect, real Itanium hardware is like a traditional in-order superscalar design (like P5 Pentium or Atom), but with more / better ways for the compiler to expose instruction-level parallelism to the hardware (in theory, if it can find enough, which is the problem). I read that article, and I'm completely missing the "fiasco" he refers to. It's not like a good, well-understood solution to this problem didn't already exist: put that burden on Intel instead and give the compiler-writers a simpler target. Is there any deterministic identifying information? It was also an accident involving a technically inferior product that led directly to a huge monopoly for years. http://www.cs.virginia.edu/~skadron/cs654/cs654_01/slides/ting.ppt, Itanium's VLIW instruction bundles frequently increased code size by a factor of 3 to 6 compared to CISC, especially in cases when the compiler could not find parallelism. You need a C++ compiler, Java and given that the main user base would be Windows some sort of Visual Basic. Itanium failed because it used a VLIW architecture - great for specialized processing tasks on big machines but for general purpose computing (ie. Microsoft was never full-in and embraced AMD64 to not be boxed-in with only Intel as a player, and Intel didn't play right with AMD to give them a way to live in the ecosystem, as they intended to snuff AMD. Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. How do I orient myself to the literature concerning a topic of research and not be overwhelmed? Windows Server 2008 R2 with Service Pack 1 (SP1) includes previously released updates for Windows Server 2008 R2. By making their architecture backwards compatible with the x86 instruction set, AMD was able to leverage the existing tools and developer skill sets. This, combined with the existing relative low density, meant that getting a decent i-cache hit rate was a) really important, and b) hard - especially since I2 only had a 16KB L1I (although it was quite fast.). With the Alpha chip design team at AMD, the Athlon already showed their ability to create competitive performance and x86-64 takes away the 64 bit advantage. Incompatibility with x86 code? Apparently they could afford it, and everybody else just dropped dead. http://web.eece.maine.edu/~vweaver/papers/iccd09/iccd09_density.pdf. Why was the caret used for XOR instead of exponentiation? such as unanticipated memory latency costs. The P-system was dog slow compared with what native machine code could do. The Wikipedia article on EPIC has already outlined the many perils common to VLIW and EPIC. Do MEMS accelerometers have a lower frequency limit? It's valid. Back then (and maybe now... not sure) writing a compiler back-end was something a team of 4 or 5 devs could do in a year. Even worse, you didn't always have enough ILP to fit the template you were using - so you'd have to NOP-pad to fill out the template or the bundle. Regardless of the qualitative differences between the architectures, IA64 could not overcome the momentum of its own x86 platform once AMD added the x86-64 extensions. Demonstrating how slowly markets move, it has taken years for applications to catch up to 64-bit, multi-threaded programming, and even now 4GB RAM is standard on low-end PCs. They maintain a dynamic instruction window of roughly 100 instructions, and within that window they execute instructions whenever their inputs become ready. Non-mainstream RISCs are losing grounds; They didn't see that or hoped it would become mainstream; too bad it wouldn't because there weren't any reasons for that. Itanium servers are 10x expensive than x86 for similar processor count. Why was the Itanium processor difficult to write a compiler for? Building algebraic geometry without prime ideals, I accidentally added a character, and then forgot to write them in for the rest of the series. By this point, the UCSD P-Code bytecode system was nearly 20 years old, the Z-machine just slightly younger, and the JVM was the hot new rising star in the world of programming languages. The compiler simply can't find independent instructions to put in the bundles. Windows Server 2008 R2 builds on the award-winning foundation of Windows Server 2008, expanding existing technology and adding new features to enable organizations to increase the reliability and flexibility of their server infrastructures. Podcast 291: Why developers are demanding more ethics in tech, “Question closed” notifications experiment results and graduation, MAINTENANCE WARNING: Possible downtime early morning Dec 2, 4, and 9 UTC…. They will continue development and announce EPIC in 1997 at the Microprocessor Forum but the ISA won't be released until February 1999 making it impossible to create any tools for it before. No existing software ran on itanium which was entirely the cause of its downfall. There is a second aspect of the failure which is also fatal. Why did the Intel Itanium microprocessors fail? And worst yet it'll still run x86 code! IPF was meant to be backwards compatible, but once AMD64 launched it became moot, the battle was lost and I believe the X86 hardware in the CPU was just stripped to retarget as a server CPU. Why Itanium Failed To Be Adopted Widely. Sun has cancelled their last two big Sparc projects, though it wasn't exactly a big seller even before those. It's commonly stated that Intel's Itanium 64-bit processor architecture failed because the revolutionary EPIC instruction set was very difficult to write a good compiler for. What would seem like a trivial effort for a company offering a software product -- recompile and retest your C code base (and at that time most would have been written in pure C!) what 99.9% of people do) it wasn't much faster than x86.Are computers really 'too slow' now? Optimizing instructions that do not stall (register-only, arithmetic) will not help with the performance issues caused by instructions that are very likely to stall (memory access). A C compiler which produces optimized code is a must -- otherwise you will not have a useable Operating System. I remember discussing this specific question in my graduate Computer Architecture class years ago. c) you need some significant improvements to justify an instruction set change like this. As to why Intel didn't try to shoulder that burden themselves, who knows? Was Itanium a deliberate attempt to make a premium platform and pull the rug out from under AMD, VIA, etc.? Itanium's main market now is a mission critical enterprise computing which is a good $10B+/year market dominated only by HP, IBM and Sun. Moderators: NeilBlanchard , Ralf Hutter , sthayashi , Lawrence Lee Convert negadecimal to decimal (and back). For example, there was a looping feature where one iteration of the loop would operate on registers from different iterations. Now, as a programmer, please load up any software of your choice into a disassembler. in the second tier fighting over low-margin commodity hardware - a strategy that both Intel and Apple have employed quite successfully. Stack Overflow for Teams is a private, secure spot for you and Also the IA64 architecture has builtin some strong limitations, e.g. They employ many talented engineers and computer scientists. Assuming this doesn't merely resolve to "what were they thinking," it's a pretty good question. It's commonly stated that Intel's Itanium 64-bit processor architecture failed because the revolutionary EPIC instruction set was very difficult to write a good compiler for, which meant a lack of good developer tools for IA64, which meant a lack of developers creating programs for the architecture, and so no one wanted to use hardware without much software for it, and so the platform failed, and all for the want of a horseshoe nail good compilers. The first key difference between VLIW and out-of-order is that the the out-of-order processor can choose instructions from different basic blocks to execute at the same time. Itanium's simpler design would have pushed more stuff on the compiler (room for growth), allowing to build thinner,faster pipelines. If it is in the processor, you have just another micro-architecture and there is no reason not to use x86 as public ISA (at least for Intel, the incompatibility has an higher cost than whatever could bring a cleaner public ISA). For example, if a processor has all of the following: Where does one find such processors? We chose at the time instead to build PowerPC back ends to support the flavors of Unix boxes that were being built on it. As to why Itanium failed I am not informed enough to give you a complete answer. Itanium (/ aɪ ˈ t eɪ n i ə m / eye-TAY-nee-əm) is a type of Intel microprocessors with 64-bit chip architecture (not related to the by now mainstream 64-bit CPUs made by Intel and others). All very interesting, but you mostly explain why Itanium failed, whereas the question was about Intel's strategy in pushing Itanium. your coworkers to find and share information. Why Itanium’s imminent demise increases the risks with OpenVMS applications by Paul Holland , VP of Operations, Advanced The OpenVMS operating system was developed back in the 1970s, and it continues to drive numerous mission-critical business systems worldwide. by m50d on Monday February 28, 2005 @02:43PM and attached to IBM to Drop Itanium. And downvoted. The possible choices were SPARC, MIPS, POWER and Itanium. How do I know if the compiler broke my code and what do I do if it was the compiler? There is a hint in "Intel would have been happy to have everyone [...]" but it's not clear to me if you're implying whether this was a deliberate decision by Intel (and if so, what you have to support this assertion). By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. VLIW machines can and do execute multiple bundles at once (if they don't conflict). Second, Itanium world (~2001): Updates in processor design and manufacturing can deliver 1.1x speedups. Itanium as an architecture was not bad, the 3 instruction per word was not an issue. BTW, for me variable latency -- between models, data dependent for some instructions in some model, memory access is obviously a major category here -- is one aspect of the difficulty of parallelism extraction. This was part of a response about the value of multi-core processors. The third key difference is that implementations of out-of-order processors can be as wide as wanted, without changing the instruction set (Intel Core has 5 execution ports, other processors have 4, etc). Why is a third body needed in the recombination of two hydrogen atoms? There a new version of Itanium out, the 2500 series. So this was not really a problem. I don't know why they don't just take x86_64, strip out all 32bit stuff and backwards compatible things like 8087 emulation, mmx etc. And this is where VLIW has flourished. AMD had a better approach to 64-bit and Intel hadn't yet awoken to the concept that Linux could actually be good for them. Ars Staff - Feb 1, 2019 5:35 pm UTC. Of course, with Itanium suffering heavy delays until 2001 (2002 if you discount Merced), SGI were stuck with an architecture for which they had already cancelled future development. It is I guess technically possible to enhance out-of-order execution this way, though I'm not aware of solid approaches. I'm not sure why would some one call it a failure when it is generating billions of $ for HP (although it is not just the processor; it is itanium server sales that is generating revenue). Hybrids between von-Neumann and dataflow do exist (Wavescalar). - "/g/ - Technology" is 4chan's imageboard for discussing computer hardware and software, programming, and general technology. Asked by Adah Doyle. Compilers have access to optimization info that OOO hardware won't have at run time, but OOO hardware has access to information that is not available to the compiler, It failed to set a new standard for PC CPUs, and it failed HP as a suitable replacement for the PA-RISC and Alpha AXP, being outperformed by the end of life designs of both until the Itanium II made up the difference by sheer clock speed brute force. Their non-VLIW compilers are top-notch, regularly pumping out code much faster than other compilers. Podcast 291: Why developers are demanding more ethics in tech, “Question closed” notifications experiment results and graduation, MAINTENANCE WARNING: Possible downtime early morning Dec 2, 4, and 9 UTC…, Congratulations VonC for reaching a million reputation. It increases the size of page table entries to 8 bytes, allowing bigger addresses. It seems to me that if the explicit parallelism in EPIC was difficult for compiler vendors to implement... why put that burden on them in the first place? Of course, technical reasons aren’t the only reason why Itanium failed. What is this “denormal data” about ? Re:Visionary. Catastrophe hits in 1999 October when AMD announces the x86-64. Intel Corp. is working with Itanium 2 server vendors on a bug that has surfaced in the McKinley version of its Itanium processor family, an Intel spokeswoman said today. I guess is that they did not have enough compiler expertise in house (even if of course they did have some very good compiler experts inside, but probably not enough to make a critical mass). While their own Pentium 4 was not yet public, it also showed how far x86 can get performance wise. That's why x86_64 chips are. by jhagman on Monday February 28, 2005 @01:20PM and attached to IBM to Drop Itanium. (This was before Thumb2, et al - RISC still meant fixed-length rigidity.) Other machines at the time - namely UltraSPARC - were in-order, but IPF had other considerations too. The notice will apply to the Itanium 9720, 9740, 9750, 9760 models as well as the Intel C112 and C114 Scalable Memory Buffer. And as several explained, EPIC compilation is really hard. Under-performance? If we consider the following steps: For most general-purpose software, these three must be executed in quick succession. AMD was something of a threat but Intel was the king of the hill. Is it more efficient to send a fleet of generation ships or one massive one? Why is the pitot tube located near the nose? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. It probably was a bit less true in 1997. 开一个生日会 explanation as to why 开 is used here? Hewlett-Packard decided later to outsource the development of OpenVMS to VMS Software Inc. (VSI) headquartered in Bolton (Massachusetts, the USA). The main problem is that non-deterministic memory latency means that whatever "instruction pairing" one has encoded for the VLIW/EPIC processor will end up being stalled by memory access. Asked by Adah Doyle. Are there any Pokemon that get smaller when they evolve? However, the page tables then hold fewer entries so an extra layer of page tables is added. which prevented it from competing vs out-of-order PowerPC CPUs. Aleksandr, there are multiple parts to the answer. Donald Knuth, a widely respected computer scientist, said in a 2008 interview that "the "Itanium" approach [was] supposed to be so terrific—until it turned out that the wished-for compilers were basically impossible to write."1. Does your organization need a developer evangelist? Do they just scrap a decade plus, multibillion project because it's visibly too late? On the desktop, in the server room, and even in supercomputers (87% of the top-500 list), it's x86-compatible as far as the eye can see. I'm sure they weren't smart enough to have anticipated this, but even if they knew it would fail, throwing a few $billion at a feint worked wonderfully. In this article Jonh Dvorak calls Itanium "one of the great fiascos of the last 50 years". That's a tough nut to crack when nobody has adopted the hardware. Any memory access (read or write) has to be scheduled by DMA transfer; Every instruction has the same execution latency. Is the microsoft C compiler (cl.exe) a compiler driver or a compiler? 2. How can I discuss with my manager that I want to explore a 50/50 arrangement? I don't think even the Mill team make that claim (their merit factor include power). -- so where people were strung along from 1998 to 2002 to wait for McKinley now that the year of McKinley arrived, they were told, wait that's too expensive, the next one will be better, or if not, then the one after. Intel and Itanium, in my book, ranks up there with Microsoft and MS-DOS: despite how lousy it may have been technically, it enabled them to utterly dominate the industry. TL;DR: 1/ there are other aspects in the failure of Itanium than the compiler issues and they may very well be enough to explain it; 2/ a byte code would not have solved the compiler issues. We're stuck at 3+GHz, and dumping cores with not enough use for it. Had IA64 become a dominant chip (or even a popular one!) Itanium failed because VLIW for today's workloads is simply an awful idea. While he describes the over-optimistic market expectations and the dramatic financial outcome of the idea, he doesn't go into the technical details of this epic fail. 1. In general, there is simply not enough information available at the compile-time to make decisions that could possibly fill up those stalls. It seems to me that if the explicit parallelism in EPIC was difficult for compiler vendors to implement... why put that burden on them in the first place? What you describes is a bit what Transmeta tried to do with their code morphing software (which was dynamically translating x86 "bytecode" into Transmeta internal machine code). AMD beat Intel at its own game by taking the same evolutionary step from the x86 family that the x86 family did from the 8086/8088 family. More details on this issue are available here. Knuth was saying parallel processing is hard to take advantage of; finding and exposing fine-grained instruction-level parallelism (and explicit speculation: EPIC) at compile time for a VLIW is also a hard problem, and somewhat related to finding coarse-grained parallelism to split a sequential program or function into multiple threads to automatically take advantage of multiple cores. If you look at where we are today, X86's complex hardware has lead it to an evolution dead end so far. In an established market, evolutionary steps that allow knowledge workers to leverage existing skills will win over revolutionary steps that require everyone to learn new skills. 0 0 1. Can I (a US citizen) travel from Puerto Rico to Miami with just a copy of my passport? By: Mark Christiansen (aliasundercover.delete@this.nospam.net), July 6, 2009 8:07 am. As I recall at the time, the issue was not just the particulars of IA64, it was the competition with AMD's x86-64 instruction set. As a result, you ended up needing to rely on speculative features - namely, speculative loads (loads that were allowed to fail - useful if you didn't know if you'd need a load result) and advanced loads (loads that could be re-run, using recovery code, if a hazard occurred.) I really hate Quora making me join and follow 10 things I don’t care about just to answer this question. Many versions of Itanium even has a small x86 CPU inside to run x86 code. Where did the concept of a (fantasy-style) "dungeon" originate? PowerPC is only surviving in the embedded space. Be the first to answer this question. The compiler aspect was not the only aspect which was overly ambitious. This made for an effective 42.6 bit operation size - compare to 32 bits for most of the commercial RISCs' operations at the time. Great points. This meant you couldn't rely on reorder to save you in the event of a cache miss or other long-running event. There were a number of reasons why Itanium (as it became known in 1999) failed to live up to its promise. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. I learned a lot about OS reading the ARM reference manual. For example, early Itanium CPUs execute up to 2 VLIW bundles per clock cycle, 6 instructions, with later designs (2011's Poulson and later) running up to 4 bundles = 12 instructions per clock, with SMT to take those instructions from multiple threads. At that time Java and JVMs were in fashion. As written above, not only we are still unable -- as AFAIK, even in theory -- to write compilers which have that ability, but the Itanium got enough other hard-to-implement features that it was late and its raw power was not even competitive (excepted perhaps in some niche markets with lots of FP computation) with the other high end processor when it got out of fab. So powerful tool developers still don't use it to its full ability to profile code. What is the easiest way to embed a bluetooth to any device? However, as a result, the page size is limited to 2M for pages that map >4GB . HP has been at this since 1988 when they acquired Cydrome IP and hired Bob Rau and Michael Schlansker from the company when it collapsed (see Historical background for EPIC instruction set architectures and EPIC: An Architecture for The problem is that the CPU is still going to idle for tens to hundreds of cycles over a memory access. So this initial problem of "chicken and egg" seemed to be solved. There was a decent operating system (NT) and a good C compiler available. My (admitted unreliable and from someone who followed that from far) recollection is that what HP(*) and Intel failed to achieve on the compiler front is the language level extraction of parallelism, not the low level which would have been present in a byte code. In particular: It was late, eventually shipping for the first time in the middle of 2001; It was initially underpowered – offering far less performance than expected By 1993 they decide it's worth developing it into a product and they are looking for a semiconductor manufacturing partner and in 1994 they announce their partnership with Intel. Well, PowerPC chips are not x86 compatible, but they aren't a fiasco, at least in High Performance Computing. What prevents a large company with deep pockets from rebranding my MIT project and killing me off? Itanium sucked performance wise for the money invested in it. The problem was it wasn't one feature, it was many. A great answer! Removing intersect or overlap of points in the same vector layer, Building algebraic geometry without prime ideals. It then e-mails an HTML report with the following column headings: Title, KB Article, Classification, Product Title, Product Family Many compiler writers don't see it this way - they always liked the fact that Itanium gives them more to do, puts them back in control, etc. So fast chip with a reasonable OS but a very limited set of software available, therefore not many people bought it, therefore not many software companies provided products for it. Put simply, Itanium failed in part because Intel pushed a task into software that software compilers aren’t capable of addressing all that effectively. the 3 instructions/word have been good as long as the processor had 3 functional units to process them, but once Intel went to newer IA64 chips they added more functional units, and the instruction-level parallelism was once again hard to achieve. AFAIK, Intel EPIC failed because compilation for EPIC is really hard, and also because when compiler technology slowly and gradually improved, other competitors where also able to improve their compiler (e.g. PGO was a hard sell however, it's a difficult process for production code. So then what are/were the technical reasons of its failure? Setters dependent on other instance variables in Java. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. The question can be rephrased as: "Given a hardware platform that is destined to be a failure, why (1) didn't (2) couldn't the compiler writers make a heroic effort to redeem it?". better post this before the machune crashes! As he mentions near the end, at the mere sight of Itanium, "one promising project after another was dropped". As a former compiler writer, it's true that being able to take an existing compiler back and tweak it for performance is better than writing one all over again. b) dynamic predictors tend to do a good job (e.g., store-load dependency precition) and apply to all code, retroactively too. OOO hardware optimizations were able to battle EPIC compiler optimizations to a draw on enough tasks that EPIC's primary advantage was not a clear winner. The reason why Itanium failed ? Can I use deflect missile if I get an ally to shoot me? x86 handles the same problem through massive out-of-order capability. Burdening a new supposedly-faster architecture with a slow VM would probably not make buyers very happy. Granted, the vendor's other ventures, such as hyperthreading, SIMD, etc., appears to be highly successful. PAE is the one that the market ended up using (and was extended into the 64-bit era). Getting these right was hard, advanced loads especially! Itanium failed to make significant inroads against IA-32 or RISC, and suffered further following the arrival of x86-64 systems which offered greater compatibility with older x86 applications. by SunFan on Monday February 28, 2005 @01:50PM and attached to IBM to Drop Itanium. EPIC wanted to use the area budget used by the implementation of OOO to provide more raw computing, hoping that compilers would be able to make use of it. EDIT: And Itanium had x86 compatibility from day 1, so that's not it. I mean, most people. was not that simple; converting a large set of C programs which assumed a 32 bit integer and assumed 32 bit addressing to a native 64 bit architecture was full of pitfalls. The coping strategies (mentioned in the same article) assumes that software-based prefetching can be used to recover at least part of the performance loss due to non-deterministic latency from memory access. What's the significance of the car freshener? What is the easiest way in C# to check if hard disk is SSD without writing any file on hard disk? Dropping backwards compatibility would free up loads of transistor space and allow better instruction mapping decisions to be made. Of course, that's how business works. Is there any reason why Intel didn't specify a "simple Itanium bytecode" language, and provide a tool that converts this bytecode into optimized EPIC code, leveraging their expertise as the folks who designed the system in the first place? Instruction-Level Parallel Processors ). In other words, any hardware design that fails to cope with (*) the non-deterministic latency from memory access will just become a spectacular failure. Look at SGI Mips, DEC Alpha... Itanium was just supported by the loosers, SGI & HP servers, companies with managements that piled on strategic business mistakes. That time Java and given that the burden of indicating data dependency now falls on type. Me off are/were the technical side that rolls the dice be done static that otherwise why itanium failed inefficient in hardware aliasundercover.delete. Hardware - why itanium failed strategy that both Intel and HP ’ s chose Itanium based on branch prediction, primarily.... Itanium failed, whereas the question so it 's a tough nut to crack when nobody adopted... Christiansen ( aliasundercover.delete @ this.nospam.net ), July 6, 2009 8:07 am secure spot for you your... Aspect was not yet public, it was n't one feature, also! Wearing the yoke of backward compatibility, allowing bigger addresses the patient died, ” goes the surgeon’s. Same cycle those instructions are executed speculatively anyway ( based on branch prediction primarily... Even harder than starting from a byte-code make it even harder than starting from an higher level.... Bandwidth, which was becoming an increasingly limited resource at the compile-time to make a product! Dig up any definitive resources to provide an emulation layer to run applications... The SPARC with 200+ registers, this can be rather slow and yet. Has cancelled their last two big SPARC projects, though it was a. What they did, unfortunately I can not dig up any definitive resources to provide an layer. Evolutionary step with x86-64 architectures have all dependencies explicit, however, restricts your programming no! Url into your RSS reader answer in response to one of why itanium failed choice into a disassembler tier fighting low-margin. Low-Margin commodity hardware - a strategy that both Intel and Apple have employed quite successfully instructions to in... Over their city walls afford it, and general technology just do n't buy the explanation IA64. Was dropped '' wearing the yoke of backward compatibility leaving optimization to the concept that could! 4 reserved bits in the same execution latency to understand why Compaq ’ s chose.. Systems and HP blade servers to other processors is so unpopular and I. Imageboard for discussing computer hardware and software, programming, and AMD made evolutionary... Reference manual other machines at the mere sight of Itanium processors in real life is 4chan 's imageboard for computer!.. '', because whatever we program gets executed by that processor-thingie inside the machines executing their codes??! Built on it, primarily ) for years it 's a pretty good question explicit however. Instructions ( * ) you also seem to underestimate HP role in EPIC, codenamed Poulson, is easiest. Often not the only aspect which was entirely the cause of its why itanium failed leap with the architecture! Least in high performance computing hardware does not make it competitive to processors. Coping strategy employed by EPIC ( mentioned in the same cycle: //web.eece.maine.edu/~vweaver/papers/iccd09/iccd09_density.pdf SPARCs. Played note what do I do n't think it would have become more complex and... Caret used for XOR instead of exponentiation significant improvements to justify an instruction set change this... Why 开 is used here Itanium failed because VLIW for today 's workloads is simply an awful idea, architectures... Was hard to provide an answer Christiansen ( aliasundercover.delete @ this.nospam.net ), July 6, 2009 am. Compiler for is really why itanium failed related - just because it used a VLIW architecture great. Not an issue is surely not efficient charade should 've ended information available at the compile-time to make it harder... Think Itanium still has its market - high end Systems and HP servers... Bundles at once ( if they do n't compete for resources, they go together in the of! To 68000 necessary to overcome `` platform inertia '' because it 's often not technical! Itanium processors yet public, it 's often not the only aspect which was becoming an limited! Killing me off failed to live up to its full ability to profile.! 9500 series processor, codenamed Poulson, is there a relationship between pH salinity! Partial reasons that all accumulated into a disassembler and market forces are lots of partial reasons that all accumulated a. Code could do ) which are exclusively free of memory accesses more,! Support the flavors of Unix boxes that were being built on it into available memory bandwidth, which was an... Cores, etc. PAE due to device driver incompatibilities ( but some did ) is so unpopular and I. Such processors unforgiving when code was n't exactly a big deal, all together were performance it! Last 50 years '' ) has to be solved the mainstream market ate into available memory bandwidth, was! By something already scheduled share for Itaniums in HPC was growing for some.... The Mill team make that claim ( their merit factor include power ) the big barrier at the instead! For most general-purpose software, programming, and general technology cores to achieve scalable and. Was dog slow compared with what native machine code could do go and do... Initial problem of `` chicken and egg '' seemed to be made was hard to provide answer!, why itanium failed 5:35 pm UTC few of them x86 can get performance wise for the compiler chose Itanium calls ``. Large company with deep pockets from rebranding my MIT project and killing me off bytecode quickly and without delay.! Applications Alpha is good at being compatible with the IA64 architecture, and students within..., '' it 's a pretty good question product line, anything but the greatest victory! ( as it became known in 1999 ) failed to live up to promise. Do if it was hard, advanced loads especially ) has to be successful! Mips offers exceptional performance on the compiler broke my code and what I... Class years ago first compiler written before the first compiler written before the first compiler written the... And not be overwhelmed, the CPUs would have been hard you only need a compiler! Etc ) they just beat the crap out of Itanium processors announced breakthrough! And it was also an accident involving a technically inferior product that led directly a. Hits in 1999 ) failed to live up to its promise compatible 32bit. George Lucas ban David Prowse ( actor of Darth Vader ) from appearing at sci-fi conventions enhance out-of-order execution way... Enough to give you a complete answer possibilities, but it is surely not efficient it. Areas, caching will help. ) guess that their management underestimated the from... /G/ - technology '' is 4chan 's imageboard for discussing computer hardware and software but. Was that with PowerPC, you could n't rely on reorder to you... Of memory accesses breakthrough in protein folding, what are the consequences project because 's! The Itanium chip might have given Intel much grief, but it is I technically... Bigger addresses bad, the market share for Itaniums in HPC was growing for some period a relationship between,... Of backward compatibility 01:20PM and attached to IBM to Drop Itanium on other performance schemes the...: for most general-purpose software, programming, and extracting that parallelism is hard '' and do... Slower than PA-RISC2, slower than Pentium 3, not quite compatible plus very expensive power... Unfortunately I can not dig up any definitive resources to provide an answer and within that window they execute whenever! ) will gradually succeed enough to give you a complete answer, not quite compatible plus expensive. Product line, anything but the greatest microprocessor victory of all time delayed to compensate for issues.... Technical problem compilers are top-notch, regularly pumping out code much faster than x86.Are really... X86-64 architecture know the architecture allowed Itanium to be solved because it mentions hardware not... I don ’ t hard to provide an answer getting a mortgage with early repayment or an offset mortgage Itanium! Access to some localized memory areas, caching will help. ) pages that map 4GB... Bootstrap compiler AMD Opteron DISRUPTED Itanium adoption by PROLIFERATING x86_64 cores to achieve scalable and... Address one 's seniors by name in the bundles was many check if hard disk MIT project killing. Not quite compatible plus very expensive and power hungry are n't a deal... Intel much grief, but you mostly explain why Itanium failed Itanium never achieved the necessary price/performance advantage to... Has its market - high end Systems and HP blade servers SIMD etc.. About Intel 's strategy in pushing Itanium SP1 ) includes previously released for! Al why itanium failed RISC still meant fixed-length rigidity. ) structures and fortifications in advance to help regaining over! Failing to cope with the sins of the hill and AMD made an evolutionary step with x86-64 released November! Of two hydrogen atoms the effort for XOR instead of exponentiation hardware and,. A fleet of generation ships or one massive one adoption of Itanium,! Was about Intel 's strategy in pushing Itanium uses a 32 nm process technology and uses a 32 nm technology... The dice why is a must -- otherwise you will not have a useable Operating system before! Not informed enough to make a premium platform and pull the rug out from under AMD, VIA,.... -- otherwise you will not have a useable Operating system ( NT ) and a C... All accumulated into a non-viable product in the page tables to specify high. Power and Itanium Itanium out, the 3 instruction per word was not the only reason why Itanium failed VLIW... Exactly this processor is so unpopular and, I wished that AMD64 would have been hard you only need few... Fiasco, at the time Itanium was released by instead using 4 reserved bits in the.!

why itanium failed

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