RADEON DIRECTX 10.1Assassin Creed .Windows VISTA SP1

We took our first step on the path of enlightement by comparing the performance of single and dual X2s with SP1 installed/uninstalled (or, if you will, with DX10.1 installed/uninstalled):







16X Anisotropic filtering is enabled through the CCC for all tests (a peculiarity of AC is that it doesn't enable AF in-game when ran in its DX10 mode), with Anti-Aliasing being either off or 4 sample(the equivalent of setting Multisampling=2 in the game's .ini file, as for the 1920x1200 resolution we're using the game doesn't allow toggling AA from its menu).

Looking at the numbers, the difference that SP1 makes with AA jumps out as being quite significant. If our assumption that this is due to AC taking advantage of DX10.1 proves to be incorrect, it would be most interesting to find out what could cause such a consistent advantage. Oddly, the QuadCF configuration refused to run with AA enabled without SP1 installed, crashing the game in spite of our best efforts. Whilst our renaming trick seems to do a fine job for 2 GPUs, it's not adequate for QuadCF:


If the benefits without AA are negligible, once we enable 4X AA we see an almost 20% advantage from using DX10.1(yep, we're fairly certain that's what's happening, so from here on we'll opt to use that formulation rather than the SP1/NO SP1 one-that being said, if we're proven to be wrong in our assertion, we'll happily admit it). For all intents and purposes, this is something to write home about.

Since you guys are gifted with inquisitive minds, such feeble proof would hardly have been enough-you could easily say that there's some magic mojo other than DX10.1 at play here. In order to verify the validity of our claim that AC is the first DX10.1 supporting title, we had to test on a SM4.0 only card and see if there was some other mechanism hidden within SP1 that increased AC's performance.

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