Memory Size Scaling

We were very interested in how the additional RAM affected game performance, so we underclocked our 7800 GTX 512 to 430/1.2 (core/mem) in order to see what (if any) difference we would find between the original 7800 GTX and the new model from framebuffer size alone. We will look at 2048x1536 both with and without AA as this is the resolution where any difference was most pronounced.

As we can see from the tests, the added RAM had no real impact on performance in any game (and a slightly negative impact in D3 and Q4).

Looking at the numbers after we enable AA, there are only two games that see any slight benefit from the extra RAM alone: Black and White 2 and Day of Defeat: Source. Battlefield 2 sees a tiny boost, but this is only evident at this extreme resolution. Clearly the majority of the benefit the 7800 GTX 512 has is from core and memory clock speed.

We do want to mention that there could be slightly more benefit from the added RAM as we have still not been able to confirm that dropping the clock speeds of the 7800 GTX 512 part results in the same clock speeds all round as the 7800 GTX. If you recall from earlier articles, the 7800 GTX has multiple clocks which aren't always all adjusted when over/under clocking. It's possible that dropping the clock speed to 430 pushed some of the internal clocks lower than they are in the original 7800 GTX. This would have a minimal impact, but an impact nonetheless.

Quake 4 Performance Final Words


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  • Gogar - Saturday, November 19, 2005 - link

    The only thing i'm still wondering about is what the performance difference between the 1800XT and the 7800GTX 512 would be if a dual core processor was used.
    Since Nvidia makes use of dual core with their drivers, the gap might be even wider.. but who knows?
  • Regs - Friday, November 18, 2005 - link

    I doubt Nvidia cared about it's price/performance one bit. This card is just a spin-off to show what 512 MB's can do....(nothing). You give a GTX a 120 MHz core speed bump with a 200 MHz RAM bump and of course it's going to perform better than the GTX 256. Pure marketing. 700 dollars? What target market is this? And even better that they decided to keep the name to make it more confusing. Let's see how much money we can squeeze out of you by putting in more RAM which Vendors all ready have ordered in Bulk 8 months ago. Reply
  • Regs - Friday, November 18, 2005 - link

    In other words you are paying 300 dollars more for a GTX with a better HSF unit. Reply
  • cryptonomicon - Tuesday, November 15, 2005 - link

    awesome card, i'm a bit confused though as to what nvidia was trying to release it as though.

    the boosted clock speeds are typical of the mid-quarter 'refresher' products (same core, with boosted stats) but it also is posing as the same product but in a 512mb variation.

    i think it should have a new model name (*agree* with derek!)
  • MadAd - Tuesday, November 15, 2005 - link

    LOL! Thats what I thought, I wonder if he read the same review as we did? 2x GTs SLId are either within a couple of fps, or between 10-20 fps higher. Considering the GT is just over 200 here, I can get 2 and add an extra 50 for an sli board (over a non sli) and still save 50 notes.

    As for soundcards, well its not a soundcard review so I dont want sound complicating anything. If I was really perdantic i'd say ATs review of the motherboard showed the a8n32 to be several FPS above all the rest of the mobos currently and would skew the data higher than normal boards, but thats not the point, the point is about comparability on the same platform.

    Finally, another thanks goes to Derek for the higher resolution coverage - although some here are mystified why resolutions above 1600x1200 are mentioned, well some of us have TFTs with native resolutions of 1920x1200 and anything lower has to be either stretched or windowed- thats not what I paid all that money to do, I want fullscreen lovelyness at full res and right now, thanks to Dereks patience, I can see that the minimum setup to enjoy all current games with FSAA at 1920x1200 is 2xGTs. Even the GTX512 isnt quite man enough.
  • MadAd - Tuesday, November 15, 2005 - link

    OOps, that was in reply to:

    RE: Newegg has it!!!! by viciousvee on: Nov 14, 2005 10:53 PM
    Might want to read the Review again (just a thought) but the GT SLI pretty much beats the GTX 512mb ("NON SLI") by a few FPS... So I stand by what I said, Get "TWO" GT's (7800) and Call it a day....
  • Eidolon - Monday, November 14, 2005 - link

    I am guessing you cannot SLI this card with an existing 7800 GTX 256MB. Is this correct? Reply
  • Fluppeteer - Tuesday, November 15, 2005 - link

    ISTR Tom's tried it, and no, you can't. (Presumably the core is tweaked
    just enough that it doesn't work.)

    Maybe nVidia will fix that in a new driver?
  • jeffrey - Monday, November 14, 2005 - link


    I have been an open critic of some of your recent work, but this review was fairly solid. Don't sweat someone saying a sentence was a run-on. The review read as an unbiased work and was inquisitive where it needed to be.

    Thanks for including the disclaimer for multiple-clocks on lowering the core clock. The addition of the 256mb vs. 512mb benchmarks was a welcome addition.

    That's all,

  • ElJefe - Monday, November 14, 2005 - link

    Eh. I dont see the point of playing at 1600 yet, so I wouldnt be TOO concerned with needing to upgrade. Obviously, this is an amazing card though, so that cant be said enough.

    anything over 300 dollars for a non all-in-wonder vid card is a ripoff though. x800XL is still more than adequate. Dont listen to the hype.


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