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AMD Hardware

Are three cores better than two? 298

Posted by Hemos
Barbarian writes "That's the question that Tom's Hardware asked. They took a dual-cpu motherboard and stuck both a single and a dual core Opteron on the board, for a total of three cores. Does it work? Well, yes, when it's not crashing. It does raise the possibility of tri-core processors whilst we are waiting for the next die shrink."
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Are three cores better than two? More

Are three cores better than two?

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  • "When its not crashing" (Score:5, Funny)

    by Anonymous Coward on Monday December 05, 2005 @12:21PM (#14185417)
    If only you would lift the power supply 3 feet above the ground,.. Oh wait..
    • Courtesy of Karma Whoring Copy-Paste technologies, Inc. (Patent Pending)

      ---

      Of course, we used our complete benchmark suite and we actually found some programs that were not working properly. Pinnacle Studio Plus 9.4.3 crashed repeatedly. Auto Gordian Knot, which we use for encoding DivX or XviD video, could not start the encoding process because it obviously was not able to access our AVI file. PCMark crashed sometimes right after finishing the compression test.

      [ Flash Ad goes here :P - no, this comment was

  • Basic Math (Score:3, Funny)

    by Anonymous Coward on Monday December 05, 2005 @12:24PM (#14185437)
    Today on /. 3 > 2!!! Tommorow 4 > 3!!

  • XBox CPU? (Score:5, Interesting)

    by TangoCharlie ( 113383 ) on Monday December 05, 2005 @12:24PM (#14185438) Homepage Journal
    I thought the XBox CPU was a three-core jobby. I don't know if all the three cores are the same or whether thre are different sorts of cores for doing different sorts of things. Presumably, as long as you've got the correct glue, and can stick any number of cores on a chip. I don't think there's any need to stick (sorry!) to powers of two. Whether or not it works better efficiently becomes the issue... or rather the ability to market three vs two or four becomes the issue!

  • If 3 work... (Score:3, Insightful)

    by op12 ( 830015 ) on Monday December 05, 2005 @12:24PM (#14185443) Homepage
    Why not try 4?

  • XBox viable? (Score:5, Funny)

    by Jotii ( 932365 ) on Monday December 05, 2005 @12:25PM (#14185448) Homepage

    "Xbox 360 is a triple core, which is a pretty good indicator that this configuration is viable"

    Wasn't XBox crashing constantly?

    • Re:XBox viable? (Score:5, Funny)

      by Vengeance ( 46019 ) on Monday December 05, 2005 @12:29PM (#14185484)
      Yes, but that was due to a lack of string.
    • Heating issues.

      They didn't consider people would block the airflow to the Xbox by putting it in entertainment centers(1) or on deep carpet(2).

      1 hard to fix really.
      2 could have avoided this problem by moving intakes/outtakes up off the floor or by adding a 1" spacer at the bottom.

    • Blame the power brick (Score:5, Interesting)

      by nobodyman ( 90587 ) on Monday December 05, 2005 @01:14PM (#14185945) Homepage
      Apparently it's the mammoth power brick which causes most of the problems, coupled with people putting it in areas without good circulation (not necessarily the consumers fault... most entertainment centers are kinda cramped). Microsoft is saying that the defect rate is 3%, I'd believe something closer to 6%, but that is actually not out of the ordinary for consumer electronics.

      So, in my mind, the "viability" issues of three cores has been answered with the 360. And in fact there are Power Mac configurations that effectively give you 4 cores (2x dual-cores). However, the bigger question is whether it will be advantageous .

      With that in mind the 360 is a pretty good test-bed to see 3-core configs are worthwhile. Developers will have more incentive to exploit the potential with the assurance that the hardware will remain relatively constant (at least as far as the API is concerned... hopefully Microsoft will be able to come out with a more compact 360 in a few years).
  • That's just asking for trouble isn't it? Mixing a single core and a dual core.

    Wouldn't you expect it to be more stable, and maybe actually work, with 2 dual core CPU's on a dualie?

    Kinda having a wtf moment.
    • Combining a single-core and a dual-core on a 2-socket motherboard?

      Yes, it might be asking for trouble, but they're doing it because they can. They're nerds, that's what they do. Maybe they shoulda dumped it in liquid nitrogen or put together a cool case mod...

      On a more serious note, I worked with an outsourcing provider once that charged us per CPU, using tiered pricing for 1-3, 4-8, 9-15, etc. So, we actually asked a manufacturer if we could buy some 3-way systems.

      Alan.

    • That's the point. Theoretically everything should work just fine, but it shows that software developers just didn't imagine the scenario. The benchmarks show either performance of dual single-core, or single dual-core, or crash, and only on rare occasions performance better than any "lesser" config. It gives you little insight into the state of the PC in such config, and as such isn't really useful, you'd be stupid to use such an error-prone config anyway. But it gives a LOT of insight into the state of cur
      • >> Theoretically everything should work just fine, but it shows that software developers just didn't imagine the scenario.

        Mixing processors with different capabilities is probably a bigger problem. Application asks OS: "Do you support SSE3"? OS says: Yes. OS switches to a different processor that doesn't support SSE3. Application uses SSE3 instructions and crashes.

  • Hardware or software first? (Score:5, Insightful)

    by dada21 ( 163177 ) * <adam.dada@gmail.com> on Monday December 05, 2005 @12:26PM (#14185463) Homepage Journal
    The question can't be answered.

    In some markets, hardware is released and only then does software take advantage of it. Sometimes software never takes advantage of the new hardware because of the complexity in writing code. I remember all the MMX and the like promotions, but I never really saw any evidence that it did anything.

    In other markets, software is released and the hardware follows. I recall Quake (or was it Quake 2) and the rush months later to have a Voodoo SLI to boost framerates.

    I am sure a 3-core processor could be "better" but only if the software to support it can be easily ported from the single core or dual core versions. Will software eventually be core-transparent because of a "xCore" abstraction layer? Will software be optimized properly for the ability to take advantage of the added cores?

    I see the need for multitasking the processor side, but I also see the complexity in trying to differentiate all the different configurations a workstation may have. The more cores that are released, the more I see application-specific turn key solutions over "one version fits all." I also see the added costs in testing and developing, and who really knows if those costs lead to any savings by creating the additional cores.

    That's the point of this post -- just because something increases efficiency in one sphere doesn't mean that there is an overall savings. There is no way to properly judge if the market will see a savings overall, and if it costs much more to produce/support/service the new product, it will fail. Nothing can stop that, not even great marketing.

    • Re:Hardware or software first? (Score:5, Insightful)

      by GeckoX ( 259575 ) on Monday December 05, 2005 @12:35PM (#14185570)
      This has nothing to do with multi-core multi-cpu configurations.

      Software that currently is not multithreaded, cannot take advantage of a SINGLE multi-core chip. HOWEVER, any multithreaded app would IMMEDIATELY take advantage of the availability of dual cores and dual cpus.

      This article is about the hardware end of this, not about your favorite game that can't use it.

      • Re:Hardware or software first? (Score:4, Insightful)

        by Kjella ( 173770 ) on Monday December 05, 2005 @01:01PM (#14185824) Homepage
        Software that currently is not multithreaded, cannot take advantage of a SINGLE multi-core chip. HOWEVER, any multithreaded app would IMMEDIATELY take advantage of the availability of dual cores and dual cpus.

        This article is about the hardware end of this, not about your favorite game that can't use it.

        If that single-threaded software runs alone. As far as multithreaded apps go, that depends. Most scientific apps can scale to like to almost any number of threads, a game might not even if it is multi-threaded. Maybe you have one "game engine" thread and a "AI" thread, and nothing to work the third core with. Not too unlikely. It all depends on how much the work can be divided.

        Kjella
        • That still says absolutely nothing at all about whether one can put a pc together with a dual mb running dual core chips.

          Of course you're right, but entirely beside the point.
        • The work for a video game can be divided quite a bit. The issue is more that game programmers are used to programming for single CPU processors because 99.9% of computers and consoles had only a single processor - hopefully the XBox 360 & PS2 will change that.
    • The software strategy for taking advantage of multicore is fairly straightforward, though not simple:

      Find your cpu bound code areas. Make them multithreaded. When your application launches, ask the OS how many cores there are, and launch that number of threads.

      The challenge of course is in 'make them multithreaded'. This takes a lot of hard engineering work.
    • You don't need special software to take advantage of muliple CPUs. All you need to more threads or processes. Certainly for servers this is not a problem for the desktop if you run multiple programs at once multiple CPUs can be used. However most users don't stress even one CPU. Unless you are running a game or rendering video. One thing, I looked at iTunes and found it had 11 threads active. THese were all running on one litle 1.25Ghz G4 processor (without stressing it in the least) So even if I had

  • blaspheme (Score:5, Funny)

    by ch-chuck ( 9622 ) on Monday December 05, 2005 @12:26PM (#14185464) Homepage
    I'm sure using anything other than a power of two irritates the binary gods, at least use an even number.

  • The Conclusion... (Score:3, Informative)

    by MrRogers2 ( 538216 ) on Monday December 05, 2005 @12:27PM (#14185469)
    Pages are loading pretty slow, here's the conclusion for those who don't want to wait:
    As you could see, the fact that we used two rather different Opterons for putting together the triple core system had an impact on the benchmark results that was hard to predict. Performance depends on the level of a program's thread-optimization, but we also had a hard time with some particular benchmarks. Some did not work at all (AutoGK w/ DivX or Xvid, Pinnacle Studio 9 Plus). For others, performance was worse than that offered by a dual-core Opteron 275 configuration (such as with memory benchmarks, ScienceMark, WinRAR file compression and Windows Media Encoder). However, the majority of software we used was able to scale well thanks to the third core (which was the case with Cinebench 2003, PovRay 3.7, Cinema 4D R9 and 3DS Max 7).

  • The software that needs it... (Score:4, Interesting)

    by doormat ( 63648 ) on Monday December 05, 2005 @12:27PM (#14185473) Homepage Journal
    isnt even ready for multithreading yet.

    Gaming is where the horsepower is needed in the consumer space - and most games aren't multithreaded. An additional core wont do much in terms of performance that a second core doesn't already accomplish. You're just wasting die space and decreasing yields.

    • Re:The software that needs it... (Score:5, Interesting)

      by Surt ( 22457 ) on Monday December 05, 2005 @12:35PM (#14185555) Homepage Journal
      Most game software is multithreaded. However, it is not multi-threaded in a way that will significantly increase performance given multiple cpus.

      As one example, I worked on Diablo II, and it had at least 5 threads (there might have been even more, but I can remember what 5 threads did). I've talked to plenty of other people in the industry, and the story is the same everywhere: multithreaded, but not parallelized in the most cpu intensive areas.

      • As far as I know most games are single threaded. At least in the main game pipeline (rendering, input, simulation, network). Usually games are coded so everything in the pipeline happens in proper order. Although there surely can be a benefit to threading these operations and have critical timing stuff still happen in proper order, it's not normally done at this date simpily because most people run single core, unless you're developing for a next gen console, of course, then you can take the additional dev
        • You're basically right on for what I'm describing except:

          1) input is commonly in its own thread, and the inputs are queued for reading by the main loop.
          2) network is usually in its own thread for the same reasons.

          Do the same thing for sound and music, and you're up to 5 threads already.

          Diablo II went to the unusual length of doing some disk loading in a background thread as well. Now you're up to 6.

          But the key problem is that rendering/simulation is where 95+% of your cpu goes, and those are probably in th

    • Re:The software that needs it... (Score:5, Insightful)

      by interiot ( 50685 ) on Monday December 05, 2005 @12:38PM (#14185589) Homepage
      Lots of kids and grandmas [cbsnews.com] are getting their hands on multi-core consoles within the next year (XBox 360 = 3 processors, PS3 = 8 processors, Nintendo Revolution = 2 processors maybe). So game authors are going to be figuring the 3+ core game out soon, and Microsoft and Sony are betting money on that fact.

    • That sounds more like game programmers are wasting their time making games that don't make use of multiple CPUs. It's very clear that there are starting to be some limits reached in terms of what one CPU can do in a machine. There's a reason all these manufacturers are making dual core processors instead of making their processor faster. It's time for the programmers to change how they program.

      So, I think your comment isn't very useful, since you try to tell hardware manufacturer's that they're doing useless things instead of making the single CPU faster. And that's not true at all. It's the game programmers that are doing stupid things. Going from 1 to 2 is would've been hard to deal with before it happened. But once you have, going from 2 to x is much easier. So, testing out three and more core systems is pretty useful.

      • Most games created are for people with one cpu in their system, why bother wasting time developing for a dual core system when only 1% of your customers will use it?
        • It may be 1% today.

          It will most likely be 25% in 12 months. Well, 90% if you count PS3 and Xbox 360.

          Trust me, current games under development for release mid-2006 or later are looking at this (as are everyone developing anything for future consoles). They have to - competition will pwn their ass with much shinyer games that take advantage of the extra hardware, and their product will look dated if they don't do the same thing.

          Due to long development times, most of the games out now do not benefit, but that
      • Simply going from 2 to n cores is not that easy or rewarding as it might sound. First, it's not easy because there are many interdependencies in the way data is accessed and manipulated by games... plus most have a number of global managers for various tasks, and global data leads to lots of sync points in code.

        It's not that rewarding because the memory bandwidth and low-latency local memory must increase as well to be able to feed the computations. In fact, I will guess that even at a massive 25.6 GB/s

    • Then it's time to demand it. It seems neary every other major type of intensive software is available such that it benefits from multiple CPUs, except games. Server and workstation (digital media, engineering, etc.) software benefit, the downside being that those are more niche.

  • Why? (Score:5, Insightful)

    by jupiter_ganymede ( 741242 ) on Monday December 05, 2005 @12:29PM (#14185487)
    Why would anyone even want to do this? Most dual proc systems are designed so that the CPUs must be the same for them to work properly. Sure, this configuration is a bit cheaper than using two dual core procs, but unless you have a space CPU sitting around I really don't see the point.
    • Tom's as well as many other sites have found that regular updates, even if they are of questionable quality, are important to keep readers comming back.

      2c

  • Bad news... (Score:4, Funny)

    by voice_of_all_reason ( 926702 ) on Monday December 05, 2005 @12:31PM (#14185509)
    As a senior Death Star Engineer, I don't think this is such a good idea at all. Despire the Governor's claims that the rebellion poses no threat, having not one, but three massive vulnerabilities on our defenses is only asking for a "small, one-man fighter" to score a direct hit.

    • Re:Bad news... (Score:5, Funny)

      by breadbot ( 147896 ) on Monday December 05, 2005 @12:45PM (#14185646) Homepage
      Are you saying you have doubts about the Governor's leadership? It's people like you that are the vulnerabilities -- not the engineering in the Death Star. Have you even seen it? It's massive! It's undefeatable! Worried about a "small, one-man fighter?" Sheesh, just put a few blaster turrets on it, and that thing will be history. I can't believe people are worried about things like that. Isn't the whole point of having a new republic to get rid of the dissent that's been wasting all of our time? Sheesh.
    • I find your lack of faith...disturbing.
  • I am not sure if it was the configuration of the different CPUs, or just the ability of the operating system, but from the result charts there is significant improvement for graphics rendering applications but not as much for other applications. The benchmark tests showed significant improvement as well.

    It would have been nice if they had tested the same CPUs in all of their tests, but overall I would say the more cores the better.

  • Razor Wars (Score:5, Funny)

    by kevin_conaway ( 585204 ) on Monday December 05, 2005 @12:31PM (#14185522) Homepage
    Hehe, reminds me of The Onions article about five razor blades vs four. [theonion.com]. Interesting that they wrotes this WELL before a 5-blade razor ever came out
    • Believe it or not, there was something called the "Holey Wars" in the last century about electric irons used to iron your clothes.

      Irons would only have one hole. Then someone released one with 2. Then 3. Then 4. Etc. Manufactures were jumping all over themselves to offer the iron with the most holes (much like what happened with early transistor radios where extra transisters were just tacked on having no function so they could call it a 6 transister radio).

      Seems odd, now that most irons have so many hole

  • Completely unscientific (Score:3, Informative)

    by porkThreeWays ( 895269 ) on Monday December 05, 2005 @12:32PM (#14185532)
    First of all, they used Windows XP SP2. Why the fuck would you do that in a multicore test. Use an OS that can handle that many cores properly. XP definatly can't. Not bashing windows either. I mean if you are going to use a windows OS at least use 2003 server. And why just test one OS? Also, the triple core title is completely misleading. The AMD arch for multicore processors is much more than just two cores stuck in a single incasing (ala Intel's design). It's much more advanced and just sticking a 2nd cpu into a multicore setup is not analagous to adding another core to the tight multicore setup. It's adding a whole 'nother cpu.
    • XP can handle 2 dual core CPUs just fine, where did you get the that it can't? 2003 is just a serverfied version of XP like NT 4 workstation vs server, there very minimal differences, most of them licensing issues like concurrent SMB share connections or number of CPUs, not number of CPU cores.

  • "Asymmetric" (Score:3, Insightful)

    by 11223 ( 201561 ) on Monday December 05, 2005 @12:36PM (#14185575)
    The article refers to the system as "asymmetric" in a few places. This is not the case: SMP refers to a situation where all CPUs run a kernel, and each CPU schedules jobs for itself. In an AMP situation, one CPU is the "master" and the others are "slaves" which are scheduled, have interrupts and system calls managed by, and are otherwise controlled by the "master" CPU. It's possible to have an SMP tri-core system, and an AMP dual-core system.

    • Re:"Asymmetric" (Score:3, Informative)

      by Rufus211 ( 221883 )
      Actually a/symmetric refers to the hardware in the system, not how the OS runs. You can implement a Master/Slave kernel just as easily on an Asymmetric systems as a Symetric one. The basic idea behind SMP is that you have N identical CPUs connected to a common memory controller, and they all have equal access to main memory. Asymetric is where you have either a NUMA machine with each CPU having its own RAM, or a cluster of machines with a backbone fabric, or something similar where talking to some regions

  • 3 Coors (Score:5, Funny)

    by frovingslosh ( 582462 ) on Monday December 05, 2005 @12:44PM (#14185633)
    Well, yes, the crashing is a problem, so lets just agree that 3 Coors are better than two unless you're driving.
    • lets just agree that 3 Coors are better than two unless you're driving.

      I disagree. Zero Coors is better than any positive integer of Coors, at all times.
      • I disagree. Zero Coors is better than any positive integer of Coors, at all times.

        Looking back at my wasted teenage years, I find myself wishing for some negative Coors.

      • I didn't say anything about Zero Coors, so your comment is suspect. It could well be that Zero Coor is better than any positive number of Coors, but that three Coors is still better than two Coors, couldn't it?

  • but.. (Score:2, Funny)

    by Turn-X Alphonse ( 789240 )
    But does it run Linux and goto 11?

  • One explanation (Score:5, Insightful)

    by lmfr ( 567586 ) on Monday December 05, 2005 @12:48PM (#14185674) Journal
    From the article:

    These two processors do not only differ in the manufacturing process: Changes to the memory controller have been made during the transition from 130 to 90 nm and SSE3 extensions were added. Opteron 248 was designed for HT800 (200 MHz bus), while the Opteron 275 is capable of running HT1000. Finally, the cache size per core is different as well.

    My guess is the crashing programs are detecting SSE3 and when a thread that uses it runs in the single core processor, the application is killed for trying an "illegal instruction."

  • We have tested a car with three tires instead of four. Does it work? Well, yes, when it's not crashing.
     
      This is got to be one of the most pointless experiments ever done. Does it work? Yes it works when it's design to work, like the XBox 360. SMP stands for SYMETRICAL MULTIPROCESSOR. A dual core and a single core are not symetrical

    • Re:Are three tires better than four? (Score:5, Informative)

      by pclminion ( 145572 ) on Monday December 05, 2005 @01:12PM (#14185932)
      Yes it works when it's design to work, like the XBox 360. SMP stands for SYMETRICAL MULTIPROCESSOR. A dual core and a single core are not symetrical

      Symmetrical multiprocessing refers to the equality of each CPU in terms of running jobs. Each core has equal opportunity to schedule and execute a thread. The fact that the individual CPUs are different has nothing to do with it.

      But thanks for playing the Demonstrate Your Ignorance Of Terminology game.

    • Re:Are three tires better than four? (Score:4, Interesting)

      by lightweave ( 522226 ) on Monday December 05, 2005 @01:30PM (#14186082)
      Actually this parent should be modded down. SMP doesn't refer to dual or single core, it jsut referes to multiple CPUs in general and it doesn't matter how many of them there are. It should run on two as well as on three or fifteen (depending on the implementation of course). What is crap though is when different CPUs are used, because software most likely wont expect this, as has been already explained in another posting regarding SSE or other special optimized code. It's not surprising either, because mmost software would determine special features at startup and not at runtime. Having a special instruction set would beg the question if the performance gain is negated by constant checks if this feature is still there.

  • Why have symmetric cores? (Score:4, Informative)

    by Demon-Xanth ( 100910 ) on Monday December 05, 2005 @12:49PM (#14185686)
    Why not setup one core heavily interger optimized, and one floating point? That way you can run the FP apps like rockets, and the interger apps like lightning w/o comprimizing on either. Rather than have a long chain in the pipeline you could have paralell paths, and once an instruction is set down one path, the CPU could take the next and see if it can stick it down another path.
    • Because when you do a processor run in the millions and you have less than 10,000 users of a highly specialized core you lose money unless you charge a lot for it.

      That's why CPUs are general purpose.

      That said, the FPU on most modern processors [at least in this respect Intel Pentium 4 incuded] are actually fairly fast compared to previous generations. At least fast enough for the vast majority of their customers.

      Sure a dedicated DSP or FPU engine could do more but they would also occupy more area [e.g. les
    • Why not setup one core heavily interger optimized, and one floating point? That way you can run the FP apps like rockets, and the interger apps like lightning w/o comprimizing on either. Rather than have a long chain in the pipeline you could have paralell paths, and once an instruction is set down one path, the CPU could take the next and see if it can stick it down another path.

      Err ... you mean like the 8086/8087 or 80186/80187 or 80286/80287 or ... I'll shut up now.

    • CPUs already operate this way. Modern processors are superscalar [wikipedia.org] and have multiple execution units that specialize in different operations. The CPU also performs elaborate tricks to keep as many of these units busy at a time, like instruction reordering and register aliasing.

      However, each process has a great deal of context associated with it, and switching between these contexts is an expensive operation. Multi-core CPUs can handle the same number of processes with less context switching.

      Instructions i

  • Need an extra core for the ads... (Score:5, Insightful)

    by steevc ( 54110 ) on Monday December 05, 2005 @12:57PM (#14185786) Homepage Journal
    ...on Tom's multi-page reviews.

    I hate sites where the article occupies less than 10% of the screen area.

  • One with SSE, one without - bozos (Score:5, Insightful)

    by Animats ( 122034 ) on Monday December 05, 2005 @01:11PM (#14185928) Homepage
    What a bunch of dummies. If you mix processors with and without SSE, some programs will randomly discover, at startup, that SSE is present and enable their SSE code. Then when that program happens to execute on a processor without SSE, it will get an illegal instruction exception. The OS even tried to tell them they had an inconsistent configuration, but they bypassed that.

    Look what failed. Video compression programs, the type of code almost certain to use streaming SIMD operations.

    Try this with two identical dual processors and you should get a nice 4-CPU machine.

  • Just because you can mix different cores on a 940 mb doesn't mean you should. Have they tried a Quad Damage (2x dual core) yet?

  • Heat (Score:3, Interesting)

    by Graham1982 ( 933841 ) on Monday December 05, 2005 @01:26PM (#14186044)
    One of the problems of a dual-core processor is that it produces a substantial amount of heat. Putting a third core on the die only makes problems of this sort a lot worse. You need a very good cooling system to keep that kind of power chilled out. Next, you need software that can take advantage of that many cores to notice any noteable performance increases.

    I know replies have probably already covered this, but here it is one more time. The Xbox 360 uses 3 PowerPC cores (kind of funny for Microsoft to use PowerPC CPUs isn't it?). The new Xbox has major problems with heat, which can also be attributed to the power supply adding to the mess. A previous story said that at least one person was hanging his power supply by a string to help out, which is ridiculous.

    We have hit a brick wall so to speak at which processors have been limited. There needs to be major changes in the way that the dies are manufactured before we can attain much higher speeds while keeping stability. One option is to stop using silicon to produce the circuitry, however thus far there are no economical solutions.

    If you really need the extra processor power, network a couple of computers together and configure them to share their resources. This takes up more space, but is the only realistic answer that I can think of right now.

  • OK, I read the fine article, and I now have a question...

    Because they are running two different chips that have different cores and memory controllers, etc. I was wondering if they thought about running the two chips in opposite slots to see if there was a difference in performance. I imagine that there may be differences, perhaps even significant ones.

    • OK, I read the fine article, and I now have a question...

      Obviously not. From TFA's first page:

      Unfortunately, our first try matching the Opteron 248 and Opteron 275 failed and the BIOS complained:

      ***** Warning: non-matching MP Processor *****

      We tried exchanging the processors, moving the dual-core Opteron 275 into the first processor socket and the single core Opteron 248 into the second one. And voilá--the system did not refuse to boot any more.

  • Car analogy (Score:3, Funny)

    by Quiet_Desperation ( 858215 ) on Monday December 05, 2005 @01:56PM (#14186335)
    Well, yes, when it's not crashing.

    I'd get the same effect if I tried driving my car on the freeway with three wheels.

    Just a pointless observation. I'm good at those.

  • Am I missing something? (Score:3, Insightful)

    by hGMFliP ( 94132 ) on Monday December 05, 2005 @03:12PM (#14187015)
    Your honor, this may *seem* offtopic at first, but I do have a point to make.

    I think that the Open Source community has proven that anything will work given enough engineering hours. Case and point; I was at Phreaknic [phreaknic.info] many moons ago and saw a TRS-80 running Debian. Yay!... but now what? Would you use your Debian-laced TRS-80 to do someting? (not knockin' it.. it was actually pretty cool, but it's a pertinent example towards my point)

    Just as Debian was able to be loaded on the TRS-80, a tri-core setup will, in all likelyhood, benchmark better than a dual setup assuming that the tri-core configuration can be stabilized (which I don't doubt is possible) and the application(s) are optimized for multiple processors. Ok, by proving that, what have we accomplished? 3 are better than 2? Of course 3 are better than 2. I personally think that a *good* question to ask would be: Are there advantages to using 3 versus 4? Or what advantages could you leverage from a 2 + 1 configuration?

    Bottom line: Did you really have to do an experiment to test that?

    Seems like one of those "chickens prefer beautiful humans" research projects. Google it; the research project is there.

  • TriCore is a brand name. (Score:3, Interesting)

    by Ungrounded Lightning ( 62228 ) on Monday December 05, 2005 @06:00PM (#14188743) Journal
    Please note that "TriCore" is a brand name (of Infineon, formerly Siemens Microelectronics).

    It is an instruction set architecture (and a set of CPU cores that implement it). It is "Tri" core because it:

    1) is a RISC architecture (for high crunch in low footprint) which
    2) has instructions and data paths to do DSP work efficiently and
    3) has the interrupt / task switching mechanisms to do real-time controller work efficiently, as well.

    this gives ASIC designers a core that handles all three major sorts of embedded processing well in one package.

    I suggest we stick to "triple core" (as most of the posters so far have) to avoid confusion between a chip with three cores and this branded single core that does three jobs well.

  • Benchmarks (Score:3, Interesting)

    by Sesse ( 5616 ) <sgunderson@big[ ]t.com ['foo' in gap]> on Monday December 05, 2005 @06:54PM (#14189247) Homepage

    These are basically the oddest benchmarks I've seen in a while, and nobody even seems to notice. Take for instance the "Cinema 4D R9" test; single Opteron, dual Opteron and dual-core Opteron are basically tied (the singe single-core is even a tiny bit faster!), but dual-core+single-core Opteron is a lot faster... Shouldn't such oddities (and that's not an isolated case) be at least commented on and explained in some sort of way if you want people to buy into your statistics at all? And why didn't they benchmark the rather obvious configuration of two dual-core CPUs?

    /* Steinar */

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