Does AM2 Reduce the Impact of L2 Cache Size?

We've already seen that Socket-AM2 doesn't really impact performance except for in games, but does the higher bandwidth memory controller reduce the impact of AMD's 1MB L2 cache parts compared to its 512KB L2 cache offerings? 

 Benchmark - Athlon 64 X2 2.0GHz Socket-939 (1MB vs. 512KB Advantage)  Socket-AM2 (1MB vs. 512KB Advantage)
Cinebench 9.5 Multi-Core Rendering Test 0.2% 0%
3dsmax 7 0.3% 0.6%
Adobe Photoshop CS2 2.7% 2.5%
DivX 6.1 0% 0%
WME9 0% 1%
Quicktime 7.0.4 (H.264) 0.9% 1.3%
iTunes (MP3) 0% 0%
Quake 4 - 10x7 (SMP) 4.8% 3.5%
Oblivion - 10x7 7.5% 3.3%
F.E.A.R. - 10x7 8.6% 6.2%


In the application benchmarks there isn't really a difference in how performance scales with cache size between the two platforms, but looking at the games there is indication of a pattern that is developing.

In Quake 4, Oblivion and F.E.A.R. the 1MB L2 cache seems to make slightly more of a difference on the Socket-939 platform than on the Socket-AM2 platform.  While the 1MB cache offers a 4.8%, 7.5% and 8.6% performance advantage in those three games on the Socket-939 platform, on AM2 the advantage is cut down to 3.5%, 3.3% and 6.2% respectively.  The explanation being that with a lower latency memory controller and more available memory bandwidth, the benefits of a larger cache are reduced on Socket-AM2. 

However the differences in performance scaling that we're seeing here are small enough that once you take into account the amount of variation you can see between runs, it's not really worth concluding anything concrete based on this data.  What we do see here is a trend of the 1MB L2 cache parts doing less on Socket-AM2 than on Socket-939 (another way of looking at it is that the 512KB are doing better on AM2 than they did on 939), but the margins are small enough that we can't really say for sure what is causing the trend.

Once again, the trend only seems to impact games, as the other application tests we've run appear to be basically unaffected. 

The Question on Everyone's Mind: Is AM2 Faster? How Does the New 4000+ Stack Up?


View All Comments

  • rADo2 - Tuesday, May 23, 2006 - link

    K8L is just a marketing, nothing else. Have you seen K8L CPU? No? AMD is about 2x slower than upcomming Conroe, so they have to spread some fud, to keep their fanboys happy...

    This is the magical performance I am speaking about, AMD cannot come even close:

    Intel Conroe @ 3.9GHz: SuperPI 1M - 12.984s">

    AMD FX-57 @ 4.2GHz: SuperPI 1M - 21.992s">

    I own X2 4400+ myself (it was a good choice in 6/2005), but within last few months AMD is a very bad choice, as for the price of quite obsolete singelcore AMD you can buy dualcore Intel D930 @ 65nm, and later Conroe. I think only AMD fanboys are buying AMD now, AMD has the worst price/value ratio, and Conroe will only make this gap wider.
  • Griswold - Tuesday, May 23, 2006 - link

    Oh and yea, I run superpi all day long because its such a valuable application that earns me money! :P Reply
  • rADo2 - Tuesday, May 23, 2006 - link

    SuperPI tells A LOT about gaming performance ;) Reply
  • mesyn191 - Wednesday, May 24, 2006 - link

    SuperPi tells you nothing except how well a CPU runs SuperPi, its not a benchmark.

    Its also about as in cache and branchless as your gonna get BTW so the performance increases you can get on it by simply scaling clockspeed are impossible as well.
  • Questar - Tuesday, May 23, 2006 - link

    SuperPi is an outlier in Conroe benchmarks. Reply
  • Griswold - Tuesday, May 23, 2006 - link

    O rly? Reply
  • Griswold - Tuesday, May 23, 2006 - link

    Blablabla... Reply
  • absolsp - Tuesday, May 23, 2006 - link

    As suspected, not much of performance gain. Happy with my existing AMD setup. Reply
  • tony215 - Wednesday, May 24, 2006 - link

    likewise, I will be sticking with my 939 venice set-up until conroe is released. Even then, I will wait for some more independent conroe test/reviews before going with Intel. Reply
  • Locutus465 - Tuesday, May 23, 2006 - link

    After reading reviews of the new chipset offerings from nVidia and ATI, personally I'm glad I'm running an nForce 4 s393 board. Seems to me the new AM2 chipsets and boards are going to need some maturing before they get good. The new solutions were *not* deffinitivly better than what is out there for s939. In fact, nVidia's offering in my opinion was particularly lack luster in terms of actual performance (compared to the older nForce 4 platform). Reply

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