X-bit labs

There Will Be Speed: The Clash of Modern Multi-GPU Technologies (page 13)

Category: Video

by Alexey Stepin , Yaroslav Lyssenko, Anton Shilov

[ 03/24/2008 | 05:01 PM ]

Crysis

Hoping to see acceptable gaming performance at least on multi-GPU systems we changed the level of detail setting from Very High to High, except Shaders option which affects the image quality the most. Even in this case we decided to use no FSAA.

Unfortunately, even this measure didn’t help to improve the gaming performance here. We didn’t achieve the frame rate of 60fps, desired for playing a first-person shooter, on any of the graphics subsystems. The best we could do was 40fps and the minimal performance still remained very low. We cannot possibly talk about any gaming comfort with fluctuations like that. I have to point out that multi-GPU systems with more than 2 graphics processors didn’t work correctly here. Moreover, Nvidia GeForce 9800 GX2 Quad SLI platform refused to work in 2560x1600 resolution. Hopefully, new drivers will fix this problem.

Enemy Territory: Quake Wars

The frame rate is fixed at 30fps in this game as this is the rate at which the physical model is being updated at the server. Thus, this 30fps speed is the required minimum for playing the game.

The single GeForce 9800 GX2 boasts high efficiency. It is 50-62% ahead of the single GeForce 8800 GTS 512MB depending on resolution, which is a very good result.

The 3- and 4-way SLI and CrossFireX systems and the ATI Radeon HD 3870 X2 do not have anything great TO BOAST: they do not outperform single graphics cards and sometimes even lose to them. Besides, Nvidia GeForce 9800 GX2 Quad SLI proved unstable in 2560x1600: every time we launched the game it demonstrated different average performance ranging from 11fps to 50fps, which can hardly be considered stable.

That’s just another example of the imperfect state of multi-GPU technologies even though they’ve been around for quite a while. In fact, this proves that the homogeneous multi-GPU concept has fundamental drawbacks which cannot be eliminated even theoretically, at least with the current 3D rendering techniques.