I have the following hardware: an Intel Core 2 Duo E8400 and an AMD Radeon HD 7850. I have a dual boot of Windows 7 and Fedora 19.
I have the impression that some games on Linux, especially Left 4 Dead 2, run with an unreasonably low frame rate. So I wanted to compare the performance objectively. The "video stress test" of Counter-Strike: Source is an easy way to do that as it is directly accessible from its main menu.
I have already seen a benchmark  comparing the performance of a Nvidia GeForce GTX 660 on Linux and Windows with the video stress test. It showed the performance on Linux is slightly lower than on Windows, but I think the difference is negligible if we don't consider the results with bloom turned on.
I used the following settings to run the video stress test on both Windows 7 and Fedora 19: model, shader, texture, water, shadow detail all at the highest setting. Anti-aliasing and filtering were set at 8x. Color correction enabled, vertical sync disabled, motion blur disabled, multicore rendering enabled. HDR at full and bloom disabled. The resolution was 1680 by 1050 pixels. Driver versions were Catalyst 13.1 for Windows 7 (older, but shouldn't matter since CS:S is old too) and Catalyst 13.6 beta for Fedora 19 (yes, beta, but betas never gave me widely different performance compared to non-beta versions).
The results: 272 frames per second on Windows 7
and only 104 frames per second on Fedora 19
. Put differently the framerate on Windows 7 is 162% higher than on Fedora 19!
I knew that AMD's Linux drivers weren't as good as those from Nvidia, but this amazed me. I'd prefer to reward AMD for it's efforts on their Linux open source driver, but with these results I'm inclined to buy a Nvidia video card.
But before I jump to conclusions, can others with AMD video cards repeat this benchmark? What do you get? Might it be that there is something wrong with my system? Shouldn't I be getting higher framerates on Linux?