ATI Radeon 5870 Eyefinity6 Review - DiRT 2

Dirt 2 is the latest iteration of the Dirt rally racing series from Codemasters. Like Battle Forge, Dirt 2 is a spotlight game for ATI with the HD 5000 series. Like Battle Forge it offers proper Hor+ gameplay in Eyefinity and DX11 support. Unless the user goes into the "hardware_settings_config.xml" file and forces DX9, Dirt 2 runs in DX11 mode. Unfortunately Dirt 2 does not offer a DX10 mode. This is unfortunate, as many games show improved performance when running in DX10 vs. DX9.

The true (noticeable) DX11 features come in to play based on the user settings in the in-game graphics options. Several key features are the "Hardware Tessellated Dynamic Water" (achieved through "Ultra" quality water), "Hardware Tessellated Dynamic Cloth" (achieved through "High" quality cloth), and DX11 Accelerated HDAO (through "High" quality HDAO).

The DX11 water and cloth offer more realistic geometry and movement. The DX11 water produces actual waves in deep puddles (as the player drives through), rather than simple "swirls" in the texture surface. The DX11 cloth offers more realistic ripples and waves in the cloth material over the DX9 version. On the other hand, the DX11 HD Ambient Occlusion (HDAO) offers an accelerated computation path.

DX11 doesn't necessarily provide earth-shaking changes to gameplay. But, it provides more realistic "movement" in the world's objects - cloth, water, grass, etc. While a DX9 or DX10 game is perfectly enjoyable, the DX11 technology offers better immersion by making the "little things" more lifelike. Additionally, it offers better computation paths through increased parallelism (and better computation paths for DX10), much like DX10 offered better performance (over DX9) in games such as Far Cry 2.

Looking at the below graph, we are starting to hit the CPU limits of a stock Core i7-920. I arrive at this conclusion by seeing how the E6 CFX maxes out at about 74fps with 1680x1050, 1920x1200 and 4800x900 (3x1600x900).

Hitting 60fps

I cracked 60fps at 4800x900 @ 2xAA. I took everything set at "Ultra" down to "High", except for Water. This allowed me to maintain the tessellated water in DX11. I also lowered Post Processing from High to Low. With plenty of options, there are a number of variations available to suit your taste.