X-bit labs

There Will Be Speed: The Clash of Modern Multi-GPU Technologies (page 16)

Category: Video

by Alexey Stepin , Yaroslav Lyssenko, Anton Shilov

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

Performance in RPG

Hellgate: London

The scalability of modern multi-GPU solutions usually worsens as more GPUs are added into the system, but it’s just the opposite here starting from 1600x1200 mode: the GeForce 9800 GX2 is 35% ahead of the GeForce 8800 GTS 512MB while the pair of GeForce 9800 GX2 brings about a 100% performance boost! We don’t observe this at 1280x1024 where the GeForce 9800 GX2 is two times as fast as the single G92-based card.

ATI’s multi-GPU technology turned out a disappointment here having demonstrated minimal performance improvement compared with the single ATI Radeon HD 3870 X2 and having failed in the 4-way CrossFireX configuration at all. We didn’t manage to get any results for the latter, because every time we tried launching the game it would freeze even in the start-up menu.

The Elder Scrolls IV: Oblivion

The game loses much of its visual appeal without HDR. Although some gamers argue that point, we think TES IV looks best with enabled FP HDR and test it in this mode.

The ATI Radeon HD 3870 X2 works impeccably although there is but a small effect from a second RV670 chip in closed game environments – the tandem can’t show its real worth. The GeForce 9800 GX2 goes far ahead of the GeForce 8800 GTS 512MB only from 1920x1200 and can be even slower than the single-chip card at lower resolutions.

The effect from 4-way SLI and 3/4-way CrossFireX configurations is negative here. The minimum speed is low, especially with ATI’s solutions.

It’s different in the open game scenes. The new solutions from Nvidia, especially the Quad SLI config, suffer a terrible reduction of minimum speed: you can’t play with slowdowns like these. The CrossFireX systems are never slower than 25fps while the pair of Radeon HD 3870 X2 cards ensures superb performance even at 2560x1600.

From a practical standpoint, this behavior of CrossFireX shows it as an immature technology. It suffers terrible reduction of minimum speed in a simpler case, but delivers superb results in a more complex one. That’s the consequence of insufficient software optimizations.