L2 Cache: 4MB or 2MB?

The majority of Intel's Core 2 Duo line feature a single shared 4MB L2 cache, but the E6300 and E6400 are only equipped with a 2MB cache. Given that the Core 2 Duo doesn't have an on-die memory controller, it is more dependent on larger caches than AMD's Athlon 64 X2, which raises the question - how big of a difference is there between the 2MB L2 and 4MB L2 parts?

Our Core 2 Extreme X6800 (2.93GHz) part, like all X6800s, is unlocked so we could simulate any other Core 2 Duo clock speed with it. We managed to get our hands on a Core 2 Duo E6300 (1.86GHz/2MB) and we were in business.

The graph below features all of the benchmarks we ran on the processors in this review, showing the percent performance improvement from a Core 2 Duo E6300 (1.86GHz/2MB) to a hypothetical 1.86GHz Core 2 Duo with a 4MB L2 cache. The bar labeled "Average" is simply an average of all of the performance improvements graphed on the chart.

The 4MB L2 cache can increase performance by as much as 10% in some situations. Such a performance improvement is definitely tangible, and as applications grow larger in their working data sets then the advantage of a larger cache will only become more visible. Unfortunately, you do pay a price premium for this added performance and future proofing as the cheapest 4MB L2 part is the E6600 priced at $316.

If you're the type to upgrade often, then the extra cache is not worth it as you're not getting enough of a present day increase in performance to justify the added cost. However, if this processor will be the basis for your system for the next several years, we'd strongly recommend picking a 4MB flavor of Core 2.

The Test Memory Latency: No Integrated Memory Controller Necessary
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  • Calin - Friday, July 14, 2006 - link

    This is a bit more complicated - you could buy a $1000 FX-62, or you could buy a $316 Core2Duo, then a $150+ mainboard. If you want to run SLI, you are out of luck right now - but things might change in the immediate future. If you have NVidia SLI, you must go to Crossfire (at this moment).

    But anyway, looks like AMD can not compete in the top
  • Regs - Friday, July 14, 2006 - link

    Since the P6!!!! Makes me think if AMD actually cares about improving performance on their processors. Maybe they should scrap the Fab in New York and make a research facility instead. Start hiring interns from MIT. Do something! lol.

    I admit, even though I enjoyed AMD having the performance crown, It was a period of limited choice and limited performance gain. Who here on the free market care about 100MHz increaments? They went from a 110nm to 90nm with no performance benifit - they went from single core to the dual core X2's with no performance benifit -- they went from DDR to DDR2 with no performance improvement -- now they are going to 65nm which they also made clear they will make no changes to increase performance. AMD has really dropped the ball and they deserve what they get. I don't know why anyone, including over clockers, would want to be a AMD fan boy at the momment.
  • CKDragon - Friday, July 14, 2006 - link

    AMD went from single core to dual core with no performance benefit?

    Maybe on Planet Troll...
  • Regs - Friday, July 14, 2006 - link

    The X2 improved performance only on specific suites of software. Can you say the same about Conroe? I mean I was really able to crank up the rez in oblivion after I upgraded to an X2 *rolls eyes*.
  • JarredWalton - Friday, July 14, 2006 - link

    The performance increases you're seeing in most games on Core 2 Duo come entirely from the better architecture, not from dual processor cores. We just can't test single core performance on Core 2 because such chips don't exist and they won't until Conroe-L ships (in about a year judging by road maps -- it looks like Intel and their partners want to have time to clear out all of their NetBurst inventory first).
  • Regs - Friday, July 14, 2006 - link

    Yes, I completely agree. The only difference on the X2 compared to the single cores was encoding. Not unless you do own a 10-thousand dollar server for well...server use.
  • Calin - Friday, July 14, 2006 - link

    Being a fanboy is like a religion - you don't change your religion overnight.
    AMD cares about selling expensive processors. As long as the P4 was the opposition (especially after the Northwood days), AMD was king of hill, and sold its processors at whatever prices the market would pay. Now, Intel took that place. I hope this will change with K8L, as this will bring even lower prices for even better processors.
    Also, AMD was unable to produce enough processors, so they sold most of it for a premium. As for the move to 90nm, they got some extra frequency headroom, and lower power consumption. This also reduced their costs (too bad the cost reduction wasn't really passed to customers).
    If their move from single to dual core brought no performance benefit, tell that to companies buying dual core opterons for thousands dollars apiece.
  • segagenesis - Friday, July 14, 2006 - link

    Good lord. You might as well throw up the GAME OVER and TILT signs for AMD right now. Although I wouldnt want them to disappear from competition (I dont want us to return to expensive Intel cpu's at the same time) there isnt much I see in this article that gives AMD any advantage at the moment over Intel. Sooner or later this was bound to happen from Intel though, the Athlon 64 made a similar situation against Pentium 4 making it look pretty obsolete comparitavely at the time.

    Now assuming the prices that AMD plans to drop to are correct, perhaps they can remain compeditive for building a budget system vs. Core 2 as I would not recommend a new Pentium 4 at this point to anyone...

    quote:

    The 2.4GHz E6600, which outperformed the FX-62 in most benchmarks at stock speed costs $316, and overclocked to 4Ghz with excellent air cooling.


    That reminds me of the good ol days over overclocking the Celeron A...
  • dice1111 - Wednesday, July 19, 2006 - link

    Ahhh, yes. My old Celeron A (still overclocked and in use). I was so happy about overclocking back then. Please Intel, let me get that taste of nostalgia!!!
  • mobutu - Friday, July 14, 2006 - link

    I'd really like to upgrade to Conroe but I don't want the Intel chipset on motherboard.
    Jarred, Wesley, do you know (estimate) when you'll have a review with final 590 reference board and when we can expect motherboards with 590 Intel edtn to be available?

    Thanks in advance guys. Great Conroe review.

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