Ages ago I tried the OpenGL way to get S3TC on Voodoo5 with UT, but it had weird rainbow glitches and was slow, and also required a specific version of 3dfxogl.dll
The guy who developed the OpenGL renderer (not Loki) recently made a D3D8 version of the renderer and I'm here to report it works GREAT on my Voodoo5.
Get it from here:
http://cwdohnal.home.mindspring.com/utglr/
I'm running in 800x600x32 and the framerate is very good, not quite as good as Glide in 1024x768x16 but it actually looks better thanks to the 32bit colour and the high res textures. Interestingly, I have discovered that triple buffering gets disabled at 1024x768 - I believe this is the case with Glide/OpenGL also, which explains why the control panel setting never did anything for me. I think this is a driver or even hardware level limitation. Strange indeed.
Anyway, here are the best settings:
[D3D8Drv.D3D8RenderDevice]
ZRangeHack=True
NumAASamples=0
UseAA=False
RequestHighResolutionZ=True
UseSoftwareVertexProcessing=True
UsePureDevice=False
UseTripleBuffering=True
MaskedTextureHack=False
FrameRateLimit=0
SwapInterval=-1
UseVertexProgram=False
TexDXT1ToDXT3=False
DynamicTexIdRecycleLevel=100
CacheStaticMaps=False
UseTexPool=True
UseTexIdPool=True
UseSSE=True
BufferTileQuads=True
BufferClippedActorTris=True
SinglePassDetail=False
SinglePassFog=False
ColorizeDetailTextures=False
DetailClipping=False
UseDetailAlpha=False
DetailMax=0
RefreshRate=0
MaxTMUnits=0
NoFiltering=False
MaxAnisotropy=0
Use16BitTextures=False
UseS3TC=True
UseAlphaPalette=False
UseTrilinear=True
UsePrecache=False
UsePalette=False
UseMultiTexture=True
MaxLogTextureSize=8
MinLogTextureSize=0
MaxLogVOverU=8
MaxLogUOverV=8
OneXBlending=True
GammaCorrectScreenshots=False
GammaOffsetBlue=0.000000
GammaOffsetGreen=0.000000
GammaOffsetRed=0.000000
GammaOffset=0.000000
LODBias=0.000000
DetailTextures=True
DescFlags=0
Description=
HighDetailActors=True
Coronas=True
ShinySurfaces=True
VolumetricLighting=True