I'm having severe performance issues with several OpenGL-based applications (notably MPlayer). Texture uploads in RGB or ARGB format are -much- slower than other texture formats. Changing the output format to gl (yuv) (uses GL_LUMINANCE I think) fixes the slowness. Other OpenGL applications seem to have the same problem -- http://www.songho.ca/opengl/gl_pbo.html#unpack gives me ~26.6MB/s transfer speed.
I thought that maybe RGB textures are automatically compressed by the driver, but I couldn't find the setting to turn it off. The OpenGL settings seem to be removed from the new graphics control panel.
Where have the OpenGL settings gone and/or why are RGB textures so slow to upload?
(Using Windows 7 x64 + GMA 4500MHD, driver version 220.127.116.111)