Following the visual comparison between the DirectX 9 and DirectX 11 mode of Colin McRae: Dirt 2, PC Games Hardware now takes a look at the differences in performance of the two rendering paths.
Original article: November 24, 2009
The PC version of Colin McRae: Dirt 2 has been delayed by Codemasters so that the developers could integrate support for DirectX 11. Microsoft's new API delivers several new features some of which are used in the racing game. Yesterday PC Games Hardware already demonstrated the visual differences between DirectX 9 and DirectX 11 in Dirt 2
and now we are going to check how the performance of graphics cards is affected. Colin McRae: Dirt 2 - Graphics card benchmarks
Fortunately Dirt 2 has an integrated benchmark that delivers a workload quite similar to the actual game. With a Subaru we race against seven other cars (with active A.I.) on a track in London. Of course on this track you also get flying flags, an audience and water as well as the DirectX 11 Post Effects. We record the framerate for 60 seconds with the tool Fraps. The differences in the results of our three runs are minimal.
The comparison between DirectX 9 and DirectX 11 reveals that all HD 5000 cards run up to 50 percent faster if the DirectX 9 rendering path is used. With this DirectX mode the Radeons place themselves on ranking positions which they are expected to take: The two Radeon HD 5800s are leading followed by the Geforce GTX 285 and Geforce GTX 275. Running DirectX 9 the Radoen HD 5770 is as fast as a HD 4870 or a HD 5870 running DirectX 11. As it has been the case in Race Driver Grid, Dirt 2 is playable absolutely smoothly only at a frame rate higher than 40 fps - with a Geforce 8800 GT for example running Dirt 2 at 1680 x 1050 with anti-aliasing and anisotropic filtering isn't much fun.
SLI and Crossfire are not working correctly up to now, but AMD is already working on a appropriate driver - and Nvidia is most likely doing the same.
In the benchmark chart below we attached (DX9) and (DX11) tags to the graphics cards' names to distinguish between the results for the two modes. Update: November 30, 2009
AMD's new Hotfix Catalyst
v8.673.1 delivers Crossfire support. We check that with a Radeon HD 5970 and can confirm the effect: With this new driver under DirectX 9 the HD 5970 reaches up to 58 percent higher results as the Radeon HD 5870. But the micro stuttering of the dual GPU card is strong and 50 frames per second on the 5970 feel about as fast as 30 fps on the 5870. If running in DirectX 11 mode the AFR (Alternate Frame Rendering) apparently is not optimal yet because here the difference between HD 5970 and HD 5870 is only 30 percent.
By the way: SLI is still not working, even with the Geforce 195.62 WHQL, although the new driver fixes the game crashes originating with the 195.55.