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AMD Hardware Technology

AMD's Dual-core Athlon 64 X2 reviewed 309

Posted by Hemos
from the lots-of-reviews dept.
ChocolateJesus writes "Weeks after formally announcing its dual-core Athlon X2 desktop processor, reviews are finally trickling out. The Tech Report's coverage tests two flavors of the Athlon 64 X2 against a whopping 17 competitors, including AMD and Intel's fastest single- and dual-core offerings. They've even thrown in a handful of dual-processor systems (and dual-core, dual-processor systems) for good measure. Testing focuses on multi-threaded applications, and the X2s deliver remarkable performance. Perhaps even more impressive is the fact that unlike Intel's dual-core Pentiums, AMD's X2s consume no more power than single-core chips." Looks like this story has come out of embargo - if you've find more reviews, post them in comments.
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AMD's Dual-core Athlon 64 X2 reviewed

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  • Cooling (Score:4, Interesting)

    by Anonymous Coward on Monday May 09, 2005 @09:33AM (#12477148)
    I don't get how this can run on the same power level as the single core chips. Can someone explain on how this is possible?
    • Re:Cooling (Score:5, Informative)

      by masklinn (823351) <slashdot,org&masklinn,net> on Monday May 09, 2005 @09:41AM (#12477242)
      Specific design and use of a modified version of the most recent AMD core (Venice). Venice's consumption is much lower than it's parent (Winchester core), check the graphs, Dual Cores' power consumption is a bit higher than the 3800+ Venice processor.

      On top of that, A64 platforms are known for their low power consumption compared to Netburst based processors.
    • Re:Cooling (Score:5, Funny)

      by 0x461FAB0BD7D2 (812236) on Monday May 09, 2005 @09:41AM (#12477250) Journal
      Easy. Multi-threaded electricity.
      • Re:Cooling (Score:2, Funny)

        by Anonymous Coward
        Close, it's the quantum nature of the electrons; each core shares all it's electons. In core 0 a quantum filter is applied so computations are done on spin up electrons; core 1 uses spin down. In order to move larger numbers of cores you have to use something with more than two states -- QCD confinment makes it tricky to get the necessary free quarks. That, however, is just an engineering issue and we'll soon be able get cpu's in any color you want.

      • I knew there was something to that whole super-string theory business...
    • Re:Cooling (Score:5, Informative)

      by Kobun (668169) on Monday May 09, 2005 @09:41AM (#12477254)
      Over at Anandtech, they have a similar article up.

      http://www.anandtech.com/cpuchipsets/showdoc.aspx? i=2410&p=2 [anandtech.com]

      On that page they compare a 130nm single core Athlon to a 90nm dual core. Even under a full load, the 90nm dual core uses less power than the single core 130nm chip.
      • Re:Cooling (Score:3, Informative)

        by drakyri (727902)
        For a smaller manufacturing process (90nm), the transistors are smaller. On the single-transistor level, at least, they require less power to operate than 180 or 130nm transistors.

        Other considerations factor in to determine the power consumption (total number of transistors, other elements, arrangement, etc.), but the smaller size drops the power level quite a bit beforehand.
      • Re:Cooling (Score:3, Interesting)

        For what it is worth, those charts are moderately deceptive. Like most amatuer sites, Anandtech doesn't have the equipment to measure actual cpu power consumption. So they measured the consumption of the entire system.

        So, assuming they used the same system for all measurements and just swapped out the cpus, the relative differences are accurate. But you can not draw any conclusion about the absolute power requirements of the cpus based solely on Anandtech's review.

        Maybe no one cares, but it would be ea
    • by Brian Stretch (5304) * on Monday May 09, 2005 @09:44AM (#12477283)
      Sayeth Anandtech [anandtech.com]: ...the Athlon 64 X2 will consume less power than a 130nm Athlon 64, and less than 20% more power than a 90nm Athlon 64. Note that the Athlon 64 X2 4200+ compared here also consumes less power than all single core 90nm Intel Pentium 4 CPUs, even the Athlon 64 X2 4800+ consumes less power than all single core 90nm Pentium 4 CPUs.
    • Well, if you design them to use less power overall and make use of the fact that they're on the same chip then it'll roughly be about the same power level. Also keep in mind that a slower-running (or idle) CPU will consume less too. In actual use, both processors probably won't be running at their full speed anyway. Such techniques are already common for mobile chips so they can improve battery life.
    • Re:Cooling (Score:2, Informative)

      by Xoro (201854)

      I don't get how this can run on the same power level as the single core chips. Can someone explain on how this is possible?

      It isn't.

      Under load, the dual core system consumes about 25 watts more power than the single (178 watts vs. 154) -- and 25 watts is just less than what a single-core A64 consumes under load.

      I think the poster was looking at the numbers for idling.

      • Re:Cooling (Score:3, Interesting)

        by ThosLives (686517)
        The really interesting thing is they measured system power consumption, not chip consumption. They specified that the power supplies were the same, but the systems have different specs [techreport.com].

        It's hardly accurate to judge a CPU's performance based on a "power drawn at the wall" measurement.

        • Re:Cooling (Score:3, Informative)

          by orderb13 (792382)
          Look at the numbers for the Athlon's. They used the same had the same specs, just changed out the chips. The Dual Cores ran under less load than the FX did.
    • Most of the other responses are wrong; the manufacturing process and core revision have nothing to do with it. The single-core chips are faster (2.8GHz) than the dual-core chips (2.4GHz); since higher frequencies use much higher power, the power ends up being the same between the two chips.
    • Re:Cooling (Score:4, Insightful)

      by nokiator (781573) on Monday May 09, 2005 @02:28PM (#12480210) Journal
      Comparing the X2s against 130nm Athlon 64 is not fair. As expected, the new X2 Athlons do burn more power than a single core Athlon 64 built on the same core/process at the same frequency. The amazing thing is that the difference appears to be only around 20%, which is almost unbelievable.

      You would expect to see less than 100% increase in the case of a dual core CPU due like the shared components which are not replicated:

      - The X2 chips still have a single, 128-bit wide memory controller. Since the memory controller charges/discharges external bit lines going to DIMMs, they do burn quite a bit of power. This power consumption is not duplicated in the case of a dual core CPU.

      - The X2 chips still have a single HyperTransport bus. The power consumption of this bus is the approximately the same between a dual core and single core CPU.

      However, power scaling due to these shared components would probably not explain how a dual core chip can burn only 20% more power. For both of the above cases, you could argue that one should expect to see higher utilization of the memory bus and the HyperTransport bus, so the exact power consumption contribution is not entirely clear.

      One thing to note that, AMD Athlon 64 cores tend to burn much less power in idle state compared to Intel chips. This is probably due to choices AMD made both in architecture and process. So the fundemantal reason why AMD X2 chips have such minimal incremental power consumption over single core chips is that one of the cores is typically underutilized most of the time and therefore burns much less power.

  • Anand's Take (Score:5, Informative)

    by Anonymous Coward on Monday May 09, 2005 @09:34AM (#12477164)
    Here's Anandtech's review of the X2 [anandtech.com].
  • will they be able to outmarket AMD again?
    • will they be able to outmarket AMD again?

      Intel is obviously relying on fat vendors like Dell, but with performance like this and power consumption like that, buyers will be asking Dell what their problem is. When Dell finally cracks, you'll know Intel have spent too long fixating on their stock price rather than their products. It's a tough thing to recover from, too, and will call for a major shake-up.

      Pity is, companies which go though this usually are considerably weaker. AMD looks good, but you h

  • by Eagle5596 (575899) <slashUserNO@SPAM5596.org> on Monday May 09, 2005 @09:37AM (#12477196)
    While the AMD 64 X2 Dualcore is impressive, I am still waiting for the AMD 69 XXX Hardcore myself.

    Sorry, it just had to be said.
  • by Anonymous Coward on Monday May 09, 2005 @09:38AM (#12477213)

    No actually, they're going to be launched in June. The fact that this would be lost on the submitter was so obvious, I was able to prepare this message in advance and just paste it in.

    These look to be amazing CPUs. After the initial linpack-with-large-matrices benchmark, you have to go thirteen pages into the benchmarks at TechReport [techreport.com] to find some of note where the Intel solutions are able to score off a win!

  • Don't Forget the [H] (Score:5, Informative)

    by Unholy_Kingfish (614606) on Monday May 09, 2005 @09:39AM (#12477223) Homepage
    The cold dark [H]OCP [hardocp.com] also has their preview [hardocp.com] up.

    Or you can jump right to their conclusions [hardocp.com].

  • Rollout process (Score:5, Interesting)

    by fbody98 (881072) on Monday May 09, 2005 @09:39AM (#12477229)
    I'm relieve to see at least one thing out of this launch, and I would hope that other companies would do as much. AMD has clearly defined their rollout process so there will be no confusions and hopefully no false expectations.

    1. Announcement
    2. Technical Preview (benchmarks Appear)
    3. Launch (OEM Availability)
    4. Ramp-up and Reseller Availability

    They even give dates, if they can keep to those dates then we might actually have a product launch that doesn't antagonize the community with accusations of a 'paper launch'.

    I'd like to see more companies be more upfront about this.
  • vs (Score:3, Insightful)

    by Doc Ruby (173196) on Monday May 09, 2005 @09:41AM (#12477251) Homepage Journal
    This is all getting very complex in the "Pentium compatible" world. Where's a chart of direct CPU performance comparisons across manufacturers (Intel, AMD, etc), so I can look up a potential purchase? Eg, I see that PriceWatch has an "Athlon XP 3000" at $102, and a P4/2.26GHz at $111. How much faster/slower will my LAME encoder server run for the $9 difference? At the very least, where's a chart showing which makes/models are direct competitors?
    • Re:vs (Score:5, Informative)

      by fbody98 (881072) on Monday May 09, 2005 @09:50AM (#12477367)

      The best example of what you're looking at that i've found is at http://www23.tomshardware.com/index.html [tomshardware.com]

      It's an interactive chart of all major processors available now and plenty that aren't available, it's a good idea to compare what you might have not and what an upgrade could do for you.

  • I do a lot of reviews of dual processor machines for publications that cover 3D animation and graphics. Usually the dual processor machines kick the single proc machines to the curb in every test. Dual CPU machines also give better interactivity, and the machines we use at the studio always are dual cpu for that reason.

    This really is going to make me think twice about the need for separate CPUs. I really want to get my hands on one of these to test.
  • by amichalo (132545) on Monday May 09, 2005 @09:51AM (#12477376)
    Does dual core have to mean 2 of the SAME processor?

    I recall reading a /. comment on a previous news day that suggested using dual core to allow the OS and anti-virus software run on one proc, while applications share another, thus improving stability/security/performance.

    But does a vendor HAVE to make a dual core chip with two of the same processor? Perhaps gains could be made using a less powerful, commodity chip core and pairing it to a top of the line core.

    Costs would be lower and they could sell more of this hybrid dual core because they would only need 1 top of the line cores.

    Oh, you get what I am saying.
    • That makes sense from a logical standpoint. The problem is, virtually all cores in any given line^1 have the same production cost. The core of an Athlon 64 2800+ cost the same to produce as an Athlon 64 4000+. Essentially, all cores are the same. After fabrication, they are tested at each power level (4000, 3800, 3500, 3200, etc) and typically marked as the highest stable rating. Sometimes if the market demands more mid-low end chips, some of the higher rated cores will be re-marked to lower rated core
    • I'm sure that would be possible, but you'd need all kinds of other support chips to make it work. When both "cores" are the same, it's easy to schedule/distribute things between them. When they're not, now you have to figure out which processes are high-priority, and should run on the faster core, and which processes are low-priority, and should run on the slower core.

      Which, needless to say, is probably pretty damn hard to do. So hard, that it'll never happen.
    • by Wesley Felter (138342) <wesley@felter.org> on Monday May 09, 2005 @10:45AM (#12477894) Homepage
      But does a vendor HAVE to make a dual core chip with two of the same processor? Perhaps gains could be made using a less powerful, commodity chip core and pairing it to a top of the line core.

      But the less powerful core does not exist, so they'd have to design it. And the design cost is killer.

      However, assuming unlimited design budget and schedule, there are some academic papers showing that heterogeneous cores are a good idea.
    • dual cores but only one bus.. So you can only have one front side bus multiplier, which means both cores run at the same frequency, with the same multiplier. It's true, in a dual CPU board you can have one high end CPU, and pair it with a 'cheaper' cpu, (if the bios allows it) however, the dual core cpus work in the same motherboards as their single core counterparts, and they share a single socket, and that socket doesn't have pinouts or a configuration allowing seperate halves of the dual core to run
    • by jericho4.0 (565125) on Monday May 09, 2005 @11:23AM (#12478247)
      Yes, they have to be the same processor. The chipset design assumes that both processes are equally capable. Last time I built a dual processor machine, it was recommended that the CPUs have the same stepping number (same batch off the line).
      • by TheRaven64 (641858) on Monday May 09, 2005 @12:46PM (#12479201) Journal
        Not only that, but scheduling algorithms for heterogeneous processors are a whole lot more complicated than those for homogenous sets (see the problems with getting good performance out of HyperThreading for an example). It might be possible to do something fairly simple, like run all processes on the slow processor and migrate them to the fast one when they use more than a certain percentage of the CPU speed, but in this case why not just down-clock the faster one when it is not in use?

        The only time when heterogeneous processors are really useful is when each is better than the others at a sub-set of tasks. Current PCs are usually a set of 3 different processors in a single box[1]. They have a reasonably fast general purpose CPU, and on the same die a simple vector processor (e.g. MMX, SSE, AltiVec), which has a different instruction set to the main processor and must be invoked explicitly. They also have a highly parallel large vector processor on a separate chip, which is usually used for graphics. No automatic scheduling is performed between these - it is up to the programmer to explicitly code for each one. Ideally, a heterogeneous processing environment would require code to be JIT compiled for each processor, and then moved between them depending on run-time profiling information.

        [1] Yes, this is an oversimplification.

  • YeS! (Score:2, Funny)

    by fredan (54788)
    An 32-bit comparison of an 64-bit processor. This is exactly what I look for when I need to know which cpu to buy...
  • by Senor_Programmer (876714) on Monday May 09, 2005 @09:56AM (#12477435)
    "... AMD's X2s consume no more power than single-core chips."

    This is significant if you live in say Honolulu where electricity is 14cents/KWh or on Kauai where it's close to 22cents/KWh.
  • Windows Licenses (Score:2, Insightful)

    As I understand it M$ only allow upto 2 cpus on a standard licence. I hope they will release an update to allow for 2 dual core chips.

    • by Anonymous Coward
      Because of all the recent news regarding dual-core CPUs and the licensing implications, this question has come up a lot. Microsoft's official licensing stance remains that one die = one CPU. The company adopted this view about the same time the Pentium HTs hit the market, bringing emulated dual processing (multi-threading) to the mainstream world.
      • by prisoner-of-enigma (535770) on Monday May 09, 2005 @01:11PM (#12479473) Homepage
        Microsoft's official licensing stance remains that one die = one CPU.

        No, Microsoft's official licensing policy is one socket = one CPU. Therefore, a dual-socket Opteron motherboard with two dual-core chips would be licensed as a dual-CPU system, even though it has four separate cores.

        I think your post was trying to get that idea across, but your statement of "one die = one CPU" is misleading to that effect.

        What's odd about this is if you bought a dual-core, dual-CPU Xeon system supporting HyperThreading. If you opened up Task Manager you'd find eight CPU graphs. Not that you'd get anything near the performance of a eight-way system, though...

        Microsoft's licensing is a bright spot when it comes to commercial software and multi-core CPU's. There are several firms still clinging to the "one core = one CPU" model, and dual core chips are going to immediately make such software very expensive.

        I contacted Oracle a couple of weeks ago to clarify their position, and I was told then that dual-core chips would be considered a single CPU for the purposes of licensing. It seems that Microsoft's adherence to the "one socket = one core" idea is forcing its competitors into the same pricing model. Who woulda thunk Microsoft would actually be helpful in this situation?
  • RISC (Score:3, Interesting)

    by delirium of disorder (701392) on Monday May 09, 2005 @10:14AM (#12477583) Homepage Journal
    Packing all this circuitry will cost more in heat and fabrication costs then conventional cpus. SPARC and MIPS CPUs get more flops, mips, and overall thoroughput per watt and per millions of transistors on a die. Maybe we will see a resurgence of eligent RISC designs as dual/quad/oct core chips become more previlent.
    • There is hardware for decoding but a lot of it goes into scheduling windows, register renaming, etc... the OOE support.

      It's not quite fair to compare a cpu that doesn't have any of that to a recent x86 that does.

      Cuz you know what, an AMD64 can hold it's own against alpha just fine. And with CISC instructions it does so with less code space pollution.

      lw $0,blah
      work
      sw $0,blah

      boring...

      ADD [eax],ebx

      much more efficient ;-)

      I mean something like an ARM processor.. you won't see that at 2Ghz anytime soon [e
    • Of course, you could also put a bunch of simple, power-efficient x86 cores (VIA/Centaur C3) on one chip. It has nothing to do with RISC vs. CISC.
    • Re:RISC (Score:2, Insightful)

      by Fittysix (191672)
      A modern x86 processor is basically a RISC processor internally, the core design probably has more in common with chips mentioned in the parent than they do with the 486.

      http://arstechnica.com/cpu/4q99/risc-cisc/rvc-1.ht ml [arstechnica.com]
  • Would this chip have a usefull application in realtime video encoding/decoding? Would I be better off with a high clocked single core AMD proc? Anyone with experiance?
  • by Dr. Damage (123558) on Monday May 09, 2005 @10:38AM (#12477821)
    Sorry about our server's inability to keep up right now. We have a mirror here: http://www2.techreport.com/ [techreport.com]
  • by dtjohnson (102237) on Monday May 09, 2005 @11:30AM (#12478314)
    The performance of the AMD X2's is absolutely amazing but...will anyone really buy them? The big computer companies seem to be offering mostly P4's at about 3 Ghz using some elderly Intel core. The newspaper this morning carries an ad from Fry's Electronics offering a wimpy '2800+ Sempron with motherboard' for $69 and that's the only AMD thing listed in their ad. Can't be much money for AMD at that price. It just doesn't look like the desktop computer market cares much about performance anymore.

    AMD might be turning out some pretty good products but they are not making any money [networkworld.com] selling them and it is only a matter of time before they have to fold their tent and leave the field to Intel.

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