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
Comments Locked

97 Comments

View All Comments

  • steelmartin - Monday, November 14, 2005 - link

    I guess if you buy this card you´re doing so partly because you´re interested in running games in the hiqhest quality settings. But afaik it can´t do OpenEXR HDR and AA like in Far Cry, so I think this card is somewhat of a contradiction. Surely it depends on how the appliction uses HDR, like Valve showed with HDR and AA for everyone in Lost Coast. But I would say, not a very futureproof card then, as everyone predicts HDR will be big in games, and I guess a lot of them will use OpenEXR. Still, it will top the charts, for what that´s worth.

    And about the extra memory, how about taking the card for a spin with Call of Duty 2? Seems that game takes advantage of 512 MiB.

    /m
  • DerekWilson - Monday, November 14, 2005 - link

    The advantage ATI offers is MSAA with floating point HDR. We've already seen a game (Black and White 2) that employs AA and HDR by using Supersample FSAA, and as you pointed out Valves Source engine avoids full float render targets and still gets good results.

    The performance hit is larger with SSAA, but it is certainly possible to have HDR and AA without the ability to do MSAA on floating point/multiple render targets. And the sheer brute strenth the 7800 GTX 512 has can easily be spent on SSAA as shown (again) by Black and White 2.
  • quasarsky - Monday, November 14, 2005 - link

    i'm an ati fan but this is ridicoulous. ati just gets crushed and crushed. even the regular 7800 gtx gets crushed. but i knew something like this would happen if the 7800 was cranked up to a clockspeed close to the x1800xt. those extra 8 pipes and the extra memory bandwidth just lead to the same thing: crushing all opponents lol. man. is ati the new intel? i hope not :(. but thats how its looking currently :'(.

    ha ha i guess my x800xt aiw isn't looking so hot right now :-D.
  • George Powell - Monday, November 14, 2005 - link

    But quite useless for most people who don't run games at statospheric resolutions.

    I would really like to see this running at 2560x1600 on the Apple 30".

  • Ozenmacher - Monday, November 14, 2005 - link

    That is some pretty amazing performance. It makes my ATi X800Xl look rather pathetic...sighs
  • KaPolski - Monday, November 14, 2005 - link

    GoGo geforce 3 ti500 Woohoo!!!!! trust me it spanks the 7800 gtx 512 down to a carefully squeezed lemon :D
  • Xenoterranos - Monday, November 14, 2005 - link

    w00t! I traded my matching-numbers first-run GeForce 3 (Before they were TI'd) in for a 5900. im not upgrading till socket M2 comes a-rolling into the bargain bin.
  • LoneWolf15 - Monday, November 14, 2005 - link

    quote:

    That is some pretty amazing performance. It makes my ATi X800Xl look rather pathetic...sighs
    It's called "marketing". Don't succumb to it.

    It it a fast card? Heck yeah. Is it necessary? Far from it. I have an ATI X800XL as well, and I don't plan on switching until I have to. Game developers will continue to make games compatible with our cards for some time to come, and the only thing we'll be missing is Shader Model 3.0. So far, what I have seen of it hasn't been a big enough improvement to encourage me to go out and plunk cash down on a new card. And seeing as my gaming is now measured in hours per week (as opposed to hours per day, like when I worked in a computer store) I couldn't justify spending that kind of bread on something that isn't constantly in use.

    I think the 7800GTX 512 is a neat looking toy. But that's just it: it's a toy. I'd rather cover two car payments or two-thirds of a mortgage payment, things I NEED to spend money on
  • Pythias - Monday, November 14, 2005 - link

    quote:

    At $700 we are a little weary of recommending this part to anyone but the professional gamers and incredibly wealthy. The extra performance just isn't necessary in most cases.


    I agree. I also think the $600 dollar pricetag on the x1800xt is a bit much as well.
  • phusg - Monday, November 14, 2005 - link

    quote:

    At $700 we are a little weary of recommending this part to anyone but the professional gamers and incredibly wealthy.


    LOL. Weary != wary and in fact reads as the opposite to what I think you mean in this sentence!

Log in

Don't have an account? Sign up now