Tuesday, August 28, 2007

DX9 and DX10 performance compared

THERE ARE two evaluations of DX9 v DX10 image quality and performance out today, both of which make for interesting reading for graphics fanboys.

The first is here on FiringSquad, and compares BioShock in the two iterations of Microsoft's 3D spec, running on the GeForce 8800 and Radeon 2900. In terms of image quality, the guys were barely able to distinguish any difference whatsoever except when it comes to particle effects, such as fog and smoke. So much for new paradigms in PC gaming.

In terms of performance, what we find is that ATI is lacking behind substantially. The 1GB 2900 XT, under DX10, is given a beating by the 8800 GTS in every test except for the 2560x1600 resolution, where the numbers all flatten out due to the poor performance. In most cases, the DX10 path is marginally faster than the DX9, presumably down to performance enhancements baked in.

The second test is here at HardOCP, where Brent and Kyle put the ringers on Call of Juarez, the DX10 game that ATI has bundled with a number of 2900 XT cards. Unlike Bioshock, Juarez offers big differences in visual quality between the two DX paths. Texture quality is much higher under DX10, and the difference is likened to playing two different games. There is also a much nicer HDR lighting implementation in DX10, as well as some shinier water effects with better blending.

So, it seems, there is some difference to crow about - although it is our suspicion that, given the time and inclination, most of the flasher DX10 features could be retro-fitted without much hassle, and the differences are more a product of time and money than capability.

Under DX9, the Radeon 2900 is faster than the 8800 GTS, even the 640Mb version. The same is true under DX10, although performance overall is lower - performance drops off by as much as 30% with the high-end path enabled. Obviously, the 8800 GTX kicks them both into touch, especially when you get to higher resolutions, but it's interesting to see DAAMIT's strong showing here.

The conclusion is that not only do ATI and Nvidia share identical image quality (certainly something to be pleased about) but also that 512MB is swiftly becoming the new minimum spec for cards when talking about DX10 compatibility at any resolution above 1280x1024. All those effects need them some memory space, we suspect.

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