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Intel Quietly Adopts AMD's x86-64 392

HishamMuhammad writes "The rumors reported earlier at /. are confirmed. The latest offerings in the Pentium 4 family now support AMD's x86-64 architecture, even though Intel is not willing to admit it very openly, by using cryptic names like EM64T and (gasp) IA-32e. (The naming issue was discussed on lkml, and the consensus there was to use 'x86-64,' even though sometimes AMD refers to it as 'AMD64'). Intel's FAQ admits their implementation is basically compatible with x86-64, except for the minor differences that have always set Athlons and P4s apart. It's about time Intel jumped on AMD's bandwagon, since its homegrown 64-bit architecture seems not to be doing very well."
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Intel Quietly Adopts AMD's x86-64

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  • Just as a side note (Score:5, Interesting)

    by OverlordQ ( 264228 ) on Wednesday November 24, 2004 @05:16PM (#10912647) Journal
    Although LKML has appeared to agree on x86-64 the folks over at Debian [] appear to have gone the other way and name the arch amd64 [].
    • by Anonymous Coward on Wednesday November 24, 2004 @05:19PM (#10912676)

      The primary reason seems to be that the dashes and underscores in x86-64 and x86_64 would have caused havoc with much of thier package management software.
    • by Erik Hensema ( 12898 ) on Wednesday November 24, 2004 @05:21PM (#10912702) Homepage

      A nice and confusing name apparently only chosen because the debian developers don't like intel for what they did (namely copying the amd64 and forgetting to mention that fact in their press releases).

      I prefer the nice vendor-neutral x86-64.

      • x86 is vendor-neutral? Aren't "386", "486" "586" Intel brand names?

        IMHO, just like we give credit for Intel by calling it "the x86 architecture", we should give credit to AMD for the amd64 architecture. NetBSD too prefers amd64 [].
      • No, that is not why. (Score:3, Interesting)

        by Anonymous Coward
        They chose AMD64 because that is the name of the platform. AMD came up with the platform, and thus named it how they chose. Plenty of people supported AMD64 before Intel made compatable chips, and it would be stupid to renamed the arch just to please Intel after the fact. Kinda like how i386 is called i386, since Intel made it.

        And given that AMD at least supports open source, and donates hardware to linux distros and BSD projects, and intel are complete assholes about even trying to get docs for hardwar
      • by Phleg ( 523632 )

        A nice and confusing name apparently only chosen because the debian developers don't like intel for what they did (namely copying the amd64 and forgetting to mention that fact in their press releases).

        Well, that and having to rearchitecture and rewrite virtually all of their package management software. But your theory is good, too. Don't let the truth get in your way there, bucko.

      • by niko9 ( 315647 ) on Wednesday November 24, 2004 @06:11PM (#10913259)

        A nice and confusing name apparently only chosen because the debian developers don't like intel for what they did (namely copying the amd64 and forgetting to mention that fact in their press releases).

        I prefer the nice vendor-neutral x86-64.

        Names of arches in Debian:

        alpha ("alpha" - Alpha Processor, Inc) I think this company is defunct.
        amd64 ("amd(64)" - AMD)
        arm ("arm" - ARM , Ltd.)
        hppa ("hp(pa)" - Hewlett Packard)
        i386 ("i(ntel)386" - Intel)
        ia64 ("i(ntel)a(rchitecture)64" - Intel)
        m68k ("m(otorola)68k" - Motorola)
        mips ("mips" - Mips Technologies, Inc)
        mipsel ("mips(el)" - Mips Technologies, Inc)
        powerpc - PowerPC vendor neutral name
        sparc ("sparc" - Sparc International, Inc)
        s390 - ibm zSeries vendor neutral name I assume

        Yup, they are all vendor neutral /rolling eyes/
    • by Z303 ( 724462 )
      The Windows DDK also uses AMD64
    • by euthyphro ( 60068 ) on Wednesday November 24, 2004 @05:25PM (#10912740)
      Solaris also elected to use "amd64":
      1 $ uname -a
      SunOS xxxxxxx 5.10 s10_72 i86pc i386 i86pc
      2 $ isainfo
      amd64 i386
      3 $ isainfo -v
      64-bit amd64 applications
      sse2 sse fxsr amd_3dnowx amd_3dnow amd_mmx mmx cmov amd_sysc cx8 tsc
      32-bit i386 applications
      sse2 sse fxsr amd_3dnowx amd_3dnow amd_mmx mmx cmov amd_sysc cx8 tsc
    • by Anonymous Coward
      FreeBSD, NetBSD, and OpenBSD also call it amd64
    • So does AFS:

      $ fs sys
      Current sysname is 'amd64_linux24'

    • Linus's view (Score:5, Interesting)

      by pavon ( 30274 ) on Wednesday November 24, 2004 @06:00PM (#10913105)
      For those who missed it last time around, Linus was also tempted to call it amd64 [] in reaction to intel's handling of the subject but decided to stick with the vendor neutral x86-64.

      And yeah, this moved from the realm of rumor to fact nearly a year ago :)
  • by Folmer ( 827037 ) * on Wednesday November 24, 2004 @05:16PM (#10912650)
    How will it perform compared to AMD's chips? AFAIK AMD usually performs better clock to clock?
    • I have owned a couple AMD K7 classics, all of which fried in the past. I have never had a Pentium chip go down, not P1, P2, P4 ever.

      You'd think I buy another Pentium in the future. But nope, I think Intel has seen its hay days. I truely think the 64-bit era will be dominated by AMD.

      Only way I'll buy Intel chips again... is if I buy an Intel board. Intel chip + board has been the most ridiculously stable combination I have ever seen.

      • by ForestGrump ( 644805 ) on Wednesday November 24, 2004 @05:33PM (#10912822) Homepage Journal
        you have a gap in your logic. let me help you.

        I, Forest Grump posess in my ownership a Pentium 3, 1.0 GHZ Tulian chip. It is housed in a Dell Inspiron 8100. I have used this lap of a top for 2 and one half years.

        In that time, the DVD has died, 2 HDD have died, 2 batteries have died, 1 wlan nic has died, 1 display hindge has died, and the faithful keyboard that I was once using had died. The motherboard, although not dead, needs to be replaced (and soon because my warranty runs out in 6 months).

        I can however, attest, that the cpu is in it's original condition is currenetly running at 0.73 ghz, and shows no sign of death...yet.

      • "Only way I'll buy Intel chips again... is if I buy an Intel board. Intel chip + board has been the most ridiculously stable combination I have ever seen."

        It bloody well should be. No one should know the ins and outs of there own cpu better than Intel so it should be super stable.
        A good setup for a server would be an Intel Motherboard with an Intel CPU with an Intel nic and an Intel video board. Yes an intel videoboard. For a server who cares if it is slow. Odds are you plug it into a monitor for set up a
      • I used to run the RMA department of a medium-sized computer store in Denmark, and for every 200 AMD CPUs we sent back, we sent maybe 3-4 Intels. If only our AMD sales eclipsed the Intel sales by a factor 50, this would be okay...
        • by John Courtland ( 585609 ) on Wednesday November 24, 2004 @05:59PM (#10913100)
          AMD had that whole package cracking issue with the heatsink, though. Not really to remove blame from AMD, since the packaging was pretty shitty, but I doubt most of those were silicon issues but rather physical damage.

          I've seen my fair share of processors (far over 10,000) and I honestly can't remember a dead AMD. In fact, when I had a nasty power spike and lost 3 components and a mother board, and I had nearly cast my AMD off as fried silicon, I decided to test it on a backup board and lo and behold, it worked. Anecdotal, I know, but I think AMD makes fine silicon.
          • "AMD had that whole package cracking issue with the heatsink, though."

            Pre-AMD64 Athlons did not have a heatspreader. This actually improves thermal transfer between the CPU and the heatsink.

            If you install your heatsink carefully, it shouldn't be a problem. You have to be careful, but it's not like you don't have to do that with Intel CPUs too.
    • AMD usually performs better clock to clock?

      As much as I like AMD over Intel these days, that isn't fair to Intel. Their archtectures are significantly different.

      A fair comparison would the best match of equivalently priced processors from each company.

      An almost fair comparison would be each company's currently shiping in quantity top-of-the-line processor in a modern motherboard.

    • by gehel ( 601073 ) on Wednesday November 24, 2004 @05:29PM (#10912790) Homepage
      The question is not if it perform better for the same clock speed. The real question is to compare performance/price or performance/power consumption.
    • by cant_get_a_good_nick ( 172131 ) on Wednesday November 24, 2004 @05:37PM (#10912868)
      depends. AMD has better memory architecture for once. Generally kicks ass on most loads vs. a Xeon.
    • by ArbitraryConstant ( 763964 ) on Wednesday November 24, 2004 @05:46PM (#10912961) Homepage
      Intel performs better with media encoding stuff, AMD performs better on other things.

      Like code with branches, and code that accesses memory.
    • I don't know why this is news, but Intel already had support for AMD's 64 bit extensions in Prescott. It was hacked in late in the game so, as you would expect, does not perform well. However Intel does not expect 64 bit apps to take off for a while so they aren't overly concerned (we still don't have a 64 bit app from MS). If you want to talk about raw performance in 32 bit mode, latest AMD tends to beat out intel in many benchmarks. But if you look at realistic usage models and the benefits of hyperth
    • by DragonHawk ( 21256 ) on Wednesday November 24, 2004 @05:58PM (#10913080) Homepage Journal
      "How will it perform compared to AMD's chips? AFAIK AMD usually performs better clock to clock?"

      Comparing processors "clock for clock" has never meant a lot, and is meaning less and less all the time. Different designs do things so differently that clock rate has about as much to do with actual performance as the color of the chip package.

      The best measure of CPU performance remains the price/performance ratio. That is, for a given amount of money, how fast will a CPU perform a given task? In other words, how much bang for the buck. AMD has consistantly been beating Intel in that department for years. Sure, you might find a chip from Intel that is 10% faster, but it will cost you 80% more.

      Even comparing price/performance on just CPUs has become difficult to impossible. Core logic (especially the memory subsystem and periperal bus) have become so important, and so differentiated, that establishing an apples-to-apples CPU comparison is hard. So instead of comparing just CPUs, you have to compare CPU/chipset/memory combinations.
    • by captaineo ( 87164 ) on Wednesday November 24, 2004 @06:35PM (#10913490)
      I just got a 3.2GHz dual Xeon with EM64T. It runs the standard x86-64 Linux kernel just fine. Emulation of 32-bit software is excellent (the performance penalty is ~1%).

      In my (64-bit) rendering benchmarks, the 3.2GHz Xeon is just a tad slower than a 2.2GHz Opteron 248.

      On my benchmarks, Opteron performance benefits massively from switching to the 64-bit architecture (30-40% faster than the same software in 32-bit mode). But, on the Xeon there is virtually no difference. This leads me to believe that Intel's implementation of the 64-bit instruction set is far less optimized than AMD's. Or, perhaps GCC emits code that favors AMD's design over Intel's.
  • Struggling Intel (Score:5, Interesting)

    by mntgomery ( 620581 ) on Wednesday November 24, 2004 @05:18PM (#10912670)
    I suppose in most technical circles that always pull for the underdog and cheer when the big dog stumbles that items like this come as great news. But its appearing more and more like Intel is the one playing catch up. They may still have market share and a far wider range of products to support them, but AMD has taken the Intel bull by the horns and is beginning to bring it to its knees. Problem is, its the competition that has driven the market and without Intel, AMD has no identity. I just hope Intel can turn things around.
    • Intel still has some technology going on that AMD doesn't yet have a solid compeditor for in an area that's I'd bet will be signficantly more important than high end desktop & server processors.

      I'm obviously talking about the Pentium M's. We've seen
      some reviews recently that indicate that Intel's mobile processors even put out decent gaming performance in desktop use.

      Both companies have been muttering about moving to dual core processors. For that sort of thing, I'd cguess that starting with a lower
  • And to think.... (Score:5, Interesting)

    by ghostis ( 165022 ) on Wednesday November 24, 2004 @05:19PM (#10912681) Homepage
    ... an Intel guy I chatted with last fall said that they did not expect to put 64-bit processors in desktop machines for at least a decade. I smiled politely. ;) -ghostis
    • by kawika ( 87069 )
      That's because Intel still acts as if the world will wait for it to deliver innovations at the pace that maximizes Intel revenue.

      I have to agree with Intel that 64-bit desktops don't make a lot of sense right now. I would prefer systems that are quiet enough to be in the same room with a TV, for example. Still, this is Intel getting some of its own medicine. It didn't make sense to compare processors strictly by MHz alone, but Intel was happy to do that as long it was to their advantage. That's where I see
    • Re:And to think.... (Score:4, Interesting)

      by Ignignot ( 782335 ) on Wednesday November 24, 2004 @05:42PM (#10912918) Journal
      And several years ago, an intel guy I knew who worked as one of the P6 designers said that the designers knew that IA64 wasn't going to fly, and that AMD would simply extend the regular x86 instructions to 64 bit and pick up some market share... and then years later it comes true. It is silly to be condencending to Intel - they have some very smart people, but they're a big company and there's plenty of politics involved.
  • by darkmeridian ( 119044 ) <> on Wednesday November 24, 2004 @05:20PM (#10912686) Homepage
    Sure, AMD is ahead right now. There is incompatibility between the two 64 bit architectures, and developers may choose to design for one or the other. But the Intel FAQ is right in that Intel processors support SSE3 and HyperThreading, for which AMD has no counterpart. This is in addition to Intel performance-enhancing compilers. If developers choose to develop around Intel's 64 Bit processor, then AMD may soon find itself behind again.
    • in early 2005 Anandtech []
    • AMD have had dual core chips [] on the roadmap for sometime (I know not the same as SMT/HyperThreading), they will also add SSE3 [] at the same time. Do Intel have the on chip memory contoller? or the Glueless 4 Way systems?
    • and HyperThreading, for which AMD has no counterpart.

      Uh, dual cores on a single die?

    • There is incompatibility between the two 64 bit architectures, and developers may choose to design for one or the other

      Yeah Let me see which one the gray unwashed masses is going to pick.

      The one supported by MS's Windows or the one that is not?

      The one that came out first and by 1Q2005 will have dual processors on chip or the one that will have same arriving one years later?

      The one that has a memorable name that is fast catching on AMD64 or the one called


    • This is in addition to Intel performance-enhancing compilers.

      You mean those compilers that AMD uses for their benchmarks?

      When performance matters, you need an end to end solution. Intel delivers. However, AMD might be able to benchmark well with 64bit apps as soon as they use Intel's updated compiler.

      For those that don't know. Most all of the AMD64/Opteron bencharks were done with the Intel compiler in 32bit mode.
    • Intel has very recently announced that it will be including the x86-64 technology on its high-end processors. AMD's currently for sale mid-range processors are already 64 bit.

      Given AMD's decent size install base of 64 bit capable desktop and laptop systems, it's unlikely that any desktop software developer will choose to be intel-specific for x86-64, if anything they'll go AMD specific with "3D-NOW!".

      In the case of server specific applications, I think the story is the same for software from major vendors
    • Sounds like an Intel commercial. All we need is the annoyning bing, bing, bing, bing at the end. Hyper-Threading is really a poor-man's dual core. So why would anyone need Hyper-Threading when you actually have dual-core in the next 6 months? SSE3 is actually useful, and as it has been pointed out, is coming very soon to AMD64.
    • by BlueBiker ( 690984 ) on Wednesday November 24, 2004 @05:41PM (#10912903)
      AMD processors will soon have SSE3 [] and don't have much need for HyperThreading to make use of idle execution units as does Pentium 4. The highly efficient Pentium M doesn't need it either.

      AMD had a 1+ year head-start distributing reference materials and winning developer mind-share. They're not likely to lose their advantage anytime soon, especially as Athlon64 is faster than current EMT64 chips in 64-bit mode, is cheaper, and runs cooler.

      You can expect developers to write code that works on both architectures, it'd be unwise to release something which didn't run well on AMD's chips.
      • by Slack3r78 ( 596506 ) on Wednesday November 24, 2004 @06:25PM (#10913406) Homepage
        I'd just like to add on to this that the reason the Athlons and P-M's don't need Hyperthreading is that HT is essentially a latency hiding method to make up for the obscenely long Netburst pipeline. Basically, keeping the 30-stage pipeline full is difficult with a single thread, so allowing the processor to address multiple threads at the same time helps keep the pipeline full. I'd suggest reading Hannibal's excellent articles at Ars Technica [] if you wish to learn more on the subject.

        Essentially, I've always felt that HT is more of a marketing gimmick than it is some new revolution in computing. While it might help performance some, AMD's upcoming dual core chips will do far more to help performance as it actually *is* a multiprocessor system rather than faking it like HT. Remember, K8 was designed with multicore in mind from the start, with Netburst, it's been hacked in.
        • Not entirely .. The real purpose of SMT (the general name) is to reduce the need for complicated multiple dispatch engines. A CPU has lots of functional units on board, and it's hard to keep them all busy. Multiple dispatch helps, but is hard to design, and often requires new compilers to really shine. SMT helps too, but is easy, and works fine with existing code. This is why Sun added 4-thread SMT to their latest chips rather than make them bigger and more complicated like everyone else did (Intel, AMD
  • FYI (Score:5, Interesting)

    by remigo ( 413948 ) on Wednesday November 24, 2004 @05:20PM (#10912695)
    As an interesting side note, check out this [] story. It says that Intel reverse engineered the AMD64 architecture (which isn't terribly surprising) but then flat-out copied the documentation, even though some of their implementation didn't match up!

    Nice one, guys.
  • by __aailob1448 ( 541069 ) on Wednesday November 24, 2004 @05:25PM (#10912736) Journal
  • Itanium isn't 'bad' (Score:4, Informative)

    by vasqzr ( 619165 ) <> on Wednesday November 24, 2004 @05:25PM (#10912751)
    Sure, you can't build a $1500 Itanium box, but at the same time, the second fastest computer in the world [] is powered by Itanium processors. So is the fifth. AMD Opterons power #17.
    • Sure, you can't build a $1500 Itanium box

      I thought Intel changed the name to Itankium after the last sales figures were announced?

    • by bani ( 467531 )
      itanium price/performance is still terrible, and market penetration is basically nil. itanium was originally designed to replace ia32, but it is being forced into ever smaller niches. soon there will be no niches left for ia64 to fit into.

      intel has sunk billions and billions into this architecture, they've been banging away at ia64 for a decade now (ia64 development began in 1994). and intel has nothing to show for it yet.

      project monterey was cancelled, and support from core itanium partners has been dry
  • by ShatteredDream ( 636520 ) on Wednesday November 24, 2004 @05:26PM (#10912753) Homepage
    their glory days are now more or less behind them. No computer in my house uses Intel processors. My family has running AthlonXPs, 1 running a Sempron and 1 Powerbook with a G4. The 32bit AMD hardware is very, very affordable and perfect for tossing together something that just works and needs to be run by someone who doesn't have a lot of disposable income.

    No one I know of talks about Intel and 64bit processors except to make fun of the Itanic. The Athlon64 and Opteron processors on the other hand are the objects of lust for many of the geeks I know. When they think 64bit that they can own, they think either AMD or Apple, not Intel.
  • by Anita Coney ( 648748 ) on Wednesday November 24, 2004 @05:27PM (#10912770) Homepage

    Back on December 26, 2002, Robert X. Cringely [] stated this would happen.

  • Quietly? (Score:3, Insightful)

    by stratjakt ( 596332 ) on Wednesday November 24, 2004 @05:29PM (#10912786) Journal
    Intel's been talking about this for some time, and it's been posted on /. numerous occasions.

    I guess we're trying to paint them with a bad brush, just because. I don't see anything quiet about it.

    Do you mean quiet as in they aren't saturating the market with bullshit about how much more amazing the internet will be with 64 bit extensions and other nonsense claims designed to sucker the technically illiterate into upgrading for no reason?
  • by IGnatius T Foobar ( 4328 ) on Wednesday November 24, 2004 @05:36PM (#10912843) Homepage Journal
    One would think that Intel, better than anyone else, should know one simple fact about the computer universe:

    Try as you might, you just can't get rid of x86.

    RISC vendors failed. Intel's own RISC efforts failed. Itanium is an overengineered design that nobody wants. What did they think was going to happen?

    In the world of computers, especially PC type computers, backwards compatibility is king. That's what keeps incumbents like Intel and (especially) Microsoft on top. You'd think they'd know this better than anyone else. Has AMD beaten Intel at its own game? Time will tell.

    Look on the bright side: the complete failure of Itanium in the marketplace (let's call it what it is, even though Intel hasn't officially thrown in the towel yet) means that we won't be stuck with an entire generation of computing where Intel calls the shots. Can you imagine what would have happened if Itanium prevailed and nobody else was allowed to produce a compatible processor?
    • You might want to rethink [] calling Itanium a complete failure that no one wants.
    • by Nom du Keyboard ( 633989 ) on Wednesday November 24, 2004 @05:45PM (#10912948)
      Try as you might, you just can't get rid of x86.

      I think that's a bit overstated. They didn't just double the width of the registers and data paths. They upped the address size beyond what I'll be able to afford in the rest of my life, added more registers overall in 64-bit mode, and generally seem to have dealt with the worst constraints imposed by backward compatability with the original 8086/88 processors.

      It's hard to call an Opteron an x86 chip. More accurately it's a superset of the x86 archtecture.

      What I really wish they'd do next is what IBM pioneered with their 400 series mid-frames. In those systems with 44-bit addressing, every byte of data -- including every byte on every disc drive -- had a unique address. I thought that was a groundbreaking idea at the time.

  • And just compatible is Intel to AMD-64? IIRC Microsoft's latest beta of Win64 makes the point of stating: ...runs on Intel 32/64 bit processors now. The strong implication is that the previous Win64 releases don't.

    So does anyone know what Intel left out of their AMD-64 (Intel will hate that reference) instruction set implementation?

  • by Doc Ruby ( 173196 ) on Wednesday November 24, 2004 @05:40PM (#10912892) Homepage Journal
    Where would the car industry, and the American economy, be if we had headlines like "GM Quietly Adopts Ford's Gascap Diameter"? These interoperability issues might make short-term profits for Intel, and offer marketdroid simplified lockin strategies, but they're inefficient limits to scaling the market to encompass everyone. So longterm profits are sacrificed, as well as usability. This fruit of the Intel/AMD crosslicense agreements should be congratulated and promoted as a "best practice" that's best for everyone touched by the industry - which is practically everyone.
  • Extentions ... (Score:3, Insightful)

    by Piranhaa ( 672441 ) on Wednesday November 24, 2004 @05:42PM (#10912906)
    It was only a matter of time for them to use AMD's extention. Common now, why would they want to have 2 different 64-bit extentions on the market competing. This would just be extremely annoying to developers and such. On top of that, AMD's has been out now for quite a while, so trying to jump into the market NOW with their own wouldn't be very smart ...

    Thats my 2 dollars...
  • Old News (Score:5, Informative)

    by jbischof ( 139557 ) on Wednesday November 24, 2004 @05:42PM (#10912920) Journal
    Umm... we all new this back when Intel announced 64bit support and released their 64bit manual. I think that was in February. 2/24/1822229&tid=118&tid=142&tid=8 []

    or was it when they started shipping 64 bit Prescotts? &tid=118&tid=137&tid=126 []

    Just because it shows up on the Register it is now news again.

  • Itanium2 (Score:2, Funny)

    by dbrummer ( 570956 )
    I like how theres an ad for Itanium2 processors on the slashdot article links for HP and Microsoft not supporting Itanium. :P
    • Re:Itanium2 (Score:3, Interesting)

      by jbischof ( 139557 )
      HP *workstations* dropped support for Itanium. Itanium is doing remarkably well in the high-end server space. Checkout the increase in servers with Intel architecture in them in the Top100 supercomputers.
  • by digidave ( 259925 ) on Wednesday November 24, 2004 @05:46PM (#10912957)
    "Intel® EM64T is one of a number of platform innovations Intel is delivering"

    So... copying somebody else is "innovation". So that's the definition Microsoft has been using all these years!
  • Talk about old stuff. Man slashdot is getting behind. This stuff was anounced at Intel's development conference in like April.
  • by Anonymous Coward on Wednesday November 24, 2004 @05:50PM (#10912999)
    The Intel chips don't have an IOMMU. This means that unless the chipset provides one (none currently do) 32 bit PCI cards cannot do DMA into memory beyond 4GB, forcing the use of bounce-buffers.

    In short, 32 bit PCI cards on systems with > 4GB memory will be G L A C I A L L Y S L O W.

    On AMD64 the IOMMU remaps memory for 32 bit DMA below 0x10000000, thereby allowing 32 bit cards to access the full 64 bit address space.

    The lesson: Buy the original. Buy AMD.
    • by BobaFett ( 93158 ) on Wednesday November 24, 2004 @08:04PM (#10914273) Homepage
      It's much worse than that, unfortunately. The bounce buffers must be allocated in the low memory (below 4G for sure), and the only way to ensure that is to allocate them at boot time. Linux kernel does it with the SWIOTLB buffer. You can specify the size at boot, but after that it's fixed. If DMA ever requests more memory than the buffer has, the kernel will panic (apparently latest 2.6 kernels have some more graceful way to handle it, but in any case DMA requests cannot be fulfilled once there is no memory for bounce buffers). On the other hand, SWIOTLB memory effectively disappears from the system.

      So, if you have a nice gaming system with 256MB video card, you may need at least that much memory just for bounce buffers, or more: I'm not sure what the exact requirements are, but I've seen EM64T boxes which would be stable only if SWIOTLB is twice the size of video RAM. Half a gig of RAM not available to the system. So at least for gaming boxes, buy AMD64, don't buy EM64T.
  • by j. andrew rogers ( 774820 ) on Wednesday November 24, 2004 @05:51PM (#10913002)
    The real advantage of AMD's 64-bit system architecture has less to do with its number crunching performance and more to do with the scalability and speed of its I/O and memory architecture e.g. HyperTransport. There is not much to differentiate Intel and AMD in the absolute number crunching arena, but if you start looking at scaling memory, I/O, and the number of cores that can work together, AMD64 leaps ahead.

    If the big advantage of these new 64-bit processors is nominally found in servers, then AMD will clean house because their systems scale and perform VERY well in the server role compared to Intel. Sure, you may not be able to tell the difference between AMD and Intel on the desktop, but for most types of server loads, there is no contest. The Opterons are very, very good server systems, and for many types of loads e.g. database servers, they run rings around Xeon processors for a very low cost.

    Unless Intel matches a very competent ccNUMA and I/O fabric to their EMT64 cores, they will not be competitive where it matters.

    • by PPGMD ( 679725 ) on Wednesday November 24, 2004 @09:56PM (#10915013) Journal
      Ding ding ding... someone that actually gets it right. AMD has solved, at least in part the memory bottle neck. I have personally tested AMD Athlon 64 vs Pentium 4 HT, the Athlon 64 wipes the Pentiums nose when it comes to loading programs.

      I think Intel is realizing that because they are desperate to get DDR2 and other faster memory technologies through, but it won't help until they integrate the memory controller.

      I should note I was sceptical about the AMD move, but after comparing two exactly the same systems, and the AMD clobbering the Pentium 4, with the only difference being CPU and directly related components. AMD has a winner with it's Hyper Transport Bus, and it scales quite well, of course there is an upper limit because you still have north bridge to control IDE, AGP and other such. But it's a fix for our current issues, like the integrated L2 (and later on die) L2 cache during the Pentium time.

  • by hrm ( 26016 ) on Wednesday November 24, 2004 @06:28PM (#10913435)
    Slightly offtopic, but a few days ago Valve's Steam stuff (the bit installed on the victim's PC) ran a poll about gamer's hardware, in which I participated.

    I was very surprised by the intermediate results: 47% was running an AMD CPU (lots of them 64 bit), Intel at 51% and the rest other wacky stuff. Considering that gaming is a major drive (maybe only windows upgrades are more important --- and those are few and far between lately) in processor upgrades, I'd be worried if I were intel.

    Personally, I've been a happy AMD user since their 386-40MHz. A brief flirt with a Pentium Pro and even a fling with a CentaurHauls (or something, I remember that name from /proc/cpu) aside, it's been AMD all the time. I hope they keep doing well.
  • by MtViewGuy ( 197597 ) on Wednesday November 24, 2004 @09:04PM (#10914689)
    I think Intel is quietly adding support for the x86-64 architecture due to the fact that Microsoft will soon release a version of Windows XP that will fully support the x86-64 architecture. I believe that the target ship date of this new release is some time in the first quarter of calendar year 2005.
  • by justins ( 80659 ) on Wednesday November 24, 2004 @09:11PM (#10914732) Homepage Journal
    I've seen it mentioned here that the Intel stuff has SSE3 and Hyperthreading, and AMD has Hypertransport and pretty good I/O in general. What nobody seems to have mentioned is that Intel was planning on leaving out support for the "page table NXE bit" which enables some nifty security features, on OpenBSD anyhow:

    Does anyone know if or when Intel will remedy this? I seem to remember reading that it wasn't a permanent problem, and eventually they would add the feature or something.
  • DEC "gotcha" (Score:3, Interesting)

    by tgrigsby ( 164308 ) on Thursday November 25, 2004 @03:06AM (#10916511) Homepage Journal
    Back in the day, DEC engineers put a "gotcha" on their chip masks after seeing their designs pop up in Russian made fabs. Magnified sufficiently, you could actually read the words, "VAX: when you care enough to steal the very best."

    Sounds like AMD has earned the right to use that line...
  • by Elminst ( 53259 ) on Thursday November 25, 2004 @02:42PM (#10919342) Homepage
    I attended a one day intel channel conference last week and they talked about this when presenting the CPU roadmap for the next few quarters. They were calling it EM64.

    What was more interesting is how they seriously played it down as unimportant. It was like, "we now have 64 bit!" "But there are only 2 versions of linux and a beta version of winXP that use it so it's not really that important." "and all your apps are still 32 bit so it doesn't matter anyway"

    Basically, it's not important that we had to copy the other guys stuff and not offer it til almost a year later because nothing really important *cough*NON-microsoft*cough* runs 64 bit anyway. But we have it!! And the itanium had it a year ago! (was amusing how he threw that in too)

    My coworker and i tried not to laugh out loud.

We're living in a golden age. All you need is gold. -- D.W. Robertson.