Pherim: Haven't played in a while and now I get massive stuttering with D3D10... maybe because I updated my drivers (currently running Radeon 16.11.2)? Anyway, "normal" D3D mode still works and I don't really notice a visual difference. OpenGL gives me lighting errors and speeds up the game way too fast, though.
edit: Ok, the graphics are fine with this
OpenGL renderer, but it's still too fast.
I've never encountered this problem, but you could try forcing the game engine to generate frames at a specific rate. For example:
[OpenGLDrv.OpenGLRenderDevice]
FrameRateLimit=60
SwapInterval=1
Setting SwapInterval=1 enables vsync. Make sure that your monitor is operating at 60Hz also; some Intel drivers sneakily drop the refresh rate to 50Hz when off AC power. If any of this helps, but you find that the input lag is unacceptable, try FrameRateLimit=59. This will introduce a very slight stutter, which is extremely hard to observe in a fast-paced twitch FPS. It will, however, reduce input lag noticeably where vsync is in effect.
EDIT: If, after all this, you are still having problems then you could try the 3dfx Glide driver instead. GOG bundles nGlide with Unreal Tournament, which is a mature and stable Glide emulator. I imagine they did this in order to ensure the best possible compatibility but, for some reason, they didn't configure Unreal Tournament to load the Glide driver by default. As with some of the third-party renderers, one has to click "Show all devices" in the 3D video device selection dialog in order to see it. One can also tune nGlide's settings by running
nglide_config.exe from the game's System folder. Compared to the kentie and cwdohnal renderers, expect it to be slower but stable, and missing widescreen support.