Dirt 2 PC Demo Released, DX11 vs. DX9 Tested

The PC Demo for Codemaster's upcoming DirectX 11 racing title Dirt 2 has just hit the web and is available for download right here. If you're unfamiliar with Dirt 2, Codemaster's says this about the game, "DiRT 2 will feature a roster of contemporary off-road events, taking players to the most diverse and challenging real-world environments. This World Tour will have players competing in aggressive multi-car and intense solo races at extraordinary new locations, from canyon racing and jungle trails to city stadium-based events." To sum this up in gamer-speak, Dirt 2 is a highly anticipated racing sim, that happens to feature some incredible graphics.


Throughout the later part of its development, in both screenshots and in live demonstrations we have received of the game, Dirt 2 has impressed us with its visual quality, realism, and use of cutting edge graphics technology. In addition to a DirectX 9 code path, Dirt 2 also utilized a number of DirectX 11 features, like hardware tessellated dynamic water, animated crowd, and dynamic cloth in addition to DirectCompute 11 accelerated high definition ambient occlusion (HADO), full floating point high dynamic range (HDR) lighting, and full screen resolution post processing. Codemaster's has produced a video showing of the DirectX 11 effects in action, that you've got to check out to appreciate...

The DX11 features mentioned above affect in-game visuals in a number of ways. For example, water splashing up from the cars is rendered in more details, with more complex geometry. And the same is true for the character models in the crowd and the various flags, banners, and cloth scattered through different tracks. The full screen post processing and advanced lighting techniques also add to the overall realism of the game, but producing more true to life colors, reflections, etc.


If you remember, Dirt 2 is also the title that has been included with Radeon HD 5800 series cards. Well, the game hasn't been released just yet--that's happening later in the week--but coupons for the game have been included with the cards. Since this is one of the first new game titles that'll be able to exploit a number of the features available with AMD's latest DX11-class cards, we thought we'd take the demo for a quick spin and give you some impressions, screen caps, and preliminary performance data.

We tested the Dirt 2 PC Demo on a Core i7 965 powered rig running Windows 7 Ultimate 64-bit edition, fully updated to support DX 11 with the August 2009 redist, and the ATI Catalyst v9.11 beta hotfix drivers available here. We set the game to operate at a resolution of 1920x1200, corrected to aspect ratio to 16:10, and enabled 4X anti-aliasing for these tests. The DirectX 11 performance numbers were recorded with the game set to its "Ultra" quality mode, while the DirectX 9 numbers were recorded with the game set to its "High" quality mode. 

Radeon HD 5870 (1920x1200, 4XAA) Minimum Average
DirectX 11 49.8 FPS 58.2 FPS
DirectX 9 57.7 FPS 65.2 FPS

As you can see, performance dropped off significantly in DirectX 11 mode. Although, we feel the need to point out that our DirectX 9 numbers are somewhat lower than expected (despite being repeatable). Keep that in mind; the delta separating DX9 and DX11 performance may be larger than this.

With increased visual quality, we think it is acceptable to see some decreased performance. The real question is, however, "Are Dirt 2's DirectX-11 visual effects worth the performance hit associated with them?" The answer to that question will ultimately be in the eyes of the beholder, of course. But, in this particular instance we have to say not really. Unlike the first wave of DX10 titles that sometimes showed 50%+ performance drops in DX10 modes versus DX9, the hit here isn't as dramatic and the game remains perfectly playable. The hit is significant though and the effects are easy to miss during a fast-paced, action packed race.

If you've got a new Radeon, go grab the demo and let us know what you think.  We'd love hear your opinions of Dirt 2 in the comments.