back to article AMD CPU shoot-out: Phenom X3 and X4

The birth of AMD’s quad-core Phenom processor was plagued with problems. After a gestation period more akin to an elephant than a CPU, the new silicon popped out puking and bawling but was clearly a bit of a runt. The problem was the now-infamous TLB error that crippled performance and reduced clock speed with the result that …

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  1. Anonymous Coward
    Anonymous Coward

    Hmmmm

    The Toms article on this seemed to draw different conclusions if I remember. They seemed to find that it offered good performance per Watt and combined with price it made a good choice.

    I think their overclocking test was done differently too, with better results.

    In general I've found that these kind of chips are great for building low cost servers which run software like Apache or Sybase which thread very well. I'm not sure I'd buy one for my desktop.

  2. Anton Ivanov
    Thumb Down

    Err... Hold on...

    OK, so what is the distinct improvement as summarised in the last page if you still enable the crippling TLB workaround as described in page 1?

    That should have been fixed in B3 so if you have it on you are actually strangling the CPU.

    Can we actually have some results with the workaround disabled and some results on an OS that can make good use of 3 cores and not just 2 of them (hint - it is not Winhoze).

  3. Leo Waldock

    Three AMD cores Ok - not so for Intel

    Roger Thomas points out that Microsoft says that its 'power of two' rule for CPU cores is

    '... specific to Intel processors and do not affect AMD processors.'

    http://support.microsoft.com/default.aspx/kb/950182/en-us

    He's right, I missed it. It doesn't change my views on Phenom. Sorry.

  4. Aaron Shannon
    Thumb Down

    You need to to retest without the TLB fix enabled......

    How can you possibly call this a fair test when you have left the BIOS fix enabled??? You are effectively running a B2 stepping, and calling it a B3. Keeping this BIOS fix enabled degrades the performance by about 30%. At least disable the L3 cache in the Intel, to keep it even. What a joke.........

  5. Ben XO
    Stop

    TLB fix = disabling the L3 cache

    I was under the impression that enabling the B2 fix basically just disables the entire L3 cache; therefore you almost certainly want this fix DISABLED for a Phenom B3 otherwise it won't perform much better than a B2.

  6. Rhyd
    Thumb Down

    I don't get it

    Why was the BIOS TLB "fix" left on if the problem's fixed in B3? That's just going to give false scores.

  7. Walter Brown
    Stop

    What 9850 version did you use?

    As the title says, which version of the Phenom x4 9850 did you use for your testing? i'm typing this comment on a 9850 black edition clocked at 3.1ghz on an Asus M3A32-MVP using a Thermal-Take Big Thunder cooler and 4x1GB Crucial Ballistix, and it gives me no problems what so ever.

    With that said, i think you just gave AMD a bum rap, rerun your overclocking tests using AMD's CPU thats made for overclocking!

    Mines the one with the rusted Intel logo beneath the shiny AMD logo!

  8. Christopher E. Stith

    A bit of a cheat, yeah?

    WTF would you kill 30% of your performance for a benchmark? You've enabled a workaround for a problem your part doesn't have for what reason? Why not overclock the overclocking-specific part? Is the Q6600 actually the same price as the Phenoms or several pounds more per unit than many of them, as they are at NewEgg? ($209.99 American for the Q6600, $148.99 for the 8450, $165.99 for the 8650, the 8750 and the 9550 each for $195, $215 for the 9750, and $235 for the 9850 BE today). How much extra do you spend on an Intel-compatible motherboard?

    Since the X3 Phenoms start cheaper than the E6550 Core 2 Duo, and the X4 ones start at a little more than the E8400 C2D, where are those comparisons? You also fail to mention that the Athlon x2 and Athlon 64 x2 lines compete just fine, price per performance, with the Core 2 Duo when you knocked the Phenoms for not having a two-core part.

    AMD doesn't have the technological lead they did a few years ago, but there's no reason you can't give them a fair showing. They trail a bit in desktop benchmarks, but at street prices (in the US anyway), the performance per investment is worth considering.

  9. Jason Harvey
    Flame

    Reviewer biased in chipzilla's favor

    disabling the TLB fix for the B3 chips would give proper results. leaving this enabled shows only sheer bias in Intel's favor. Go back to benchmark school!

  10. Adrian Esdaile
    Happy

    Why test Pov-Ray?

    Sure, Pov-ray was fancy-pants back when I finished uni in '95, it was da bomb for rendering, but now...

    Testing a CPUs performance with Pov-ray shows... how good that CPU is at running Pov-ray. Do you want a prize?

    hmph, back to work, drawing & rendering in Revit & Max... NOT Pov-ray! I might play some Crysis later too.

  11. Adrien Kwok
    Stop

    Review Biased

    Like everyone have already stated before me. This review is biased and will be discredited until there is a new review with the B3 TLB "fix" disabled so that the system runs full speed since the B3 already fixed the TLB issue in the first place. Thus, there is no reason to leave the software workaround to test it against a processor that has their TLB enabled (Intel).

    Until RegHardware redo this review, this review is just a waste of bandwidth.

  12. Leo Waldock

    TLB - Flame off

    I rebuilt the test system with the Phenom X4 9850 and re-ran the tests with the TLB fix disabled.

    It made no difference to the test results or to overclocking so the only logical conclusion is that the TLB fix does not apply with B3 processors. Clearly it would be unnecessary.

    Ref the 'disables L3 cache' point - does anyone know if this is the effect of the TLB fix? I've heard this supposition a number of times but have never had a clear statement from AMD about the problem. It also doesn't explain why AMD pulled the launch of the Phenom 9700 and ploughed ahead with the 9500 and 9600.

  13. Leo Waldock

    and the official word from AMD on the TB fix

    'You (won't) be slowing the B3 Phenom’s performance, since the BIOS switching ‘knows’ that B3 does not have the TLB and therefore does not affect performance and bypasses the TLB BIOS settings.'

    Apologies for causing confusion in the first place but the figures stand.

    Adrian, I quite agree that POV-Ray is a bit old and crusty - does Revit or similar have a built in benchmark that is repeatable and transparent to the world at large?

  14. Doug Lynn

    AMD still rules in gaming IMHO!

    HI, if you go to http://www.lostcircuits.com and read their orginal Phenom reviews and later B3 reviews. The benchmarks for the Phenom beat any Intel cpu while running Unreal Engine 3 games when you used a Spider platform motherboard. I'm a gamer and I'm been sold, selling AMD cpus since 1998 when they blew away the Pentium 233Mhz.

  15. Matt

    Thanks

    Thanks for the update Leo. I read elsewhere that turning off the B2 fix at motherboard level may be necesary, but depens on your motherboard and in some cases it may be necesary to flash your BIOS with the latest version.

    Out of the three or four other reviews I read they managed between 2.8 and 3GHz with a stable system. Personaly I prefer to leave things as they are.

    One of the problems I've seen is finding Windows software that I might use and that properly multi-threads (having said which the previous comment seems to imply UT3 might).

    Anyway, I've decided to buy a B3 stepped quad core and will run some tests with Apache, Sybase and so on. So, more server oriented tests.

  16. Anonymous Coward
    Stop

    Ground control to the register, do you have shares in Intel?

    The whole point of the B3 release is to fix the TLB issue. It is no surprise your results were poor and overclocking barely worked, the TLB fix forces the CPU to read system memory instead of on chip cache! Re-run the test with the "fix" off and then you will see this chip as it was intended!!!!

  17. Tony Smith, Editor, Reg Hardware (Written by Reg staff)

    @AC

    As Leo notes in the comments above, he turned the fix off and it made no difference.

    Even AMD admits enabling the fix has no impact on B3 performance.

  18. Anonymous Coward
    Dead Vulture

    Who is responsible for those charts?

    Lets compare the chips at the same clocks speed, 4 bars, that I don't have to spend 5 minutes on each graph.

    If you want to test Cool n' Quiet on v. off, do it in a separate test, with one processor.

  19. G
    Stop

    retail prices show AMD quad same prices as Core 2 duo

    I have just checked my hardware supplier and see that around the £100 pound mark I can either get:

    An Intel Dual Core

    or

    An AMD Phenom Quad Core

    Forget the Mhz speed

    Anyone who shells out their £100 for the Dual Core (Intel) when they can get a Quad for the same price (AMD) must be smoking crack!

    Gary.

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