I dual boot Windows XP and Ubuntu. I have noticed across several
versions of Ubuntu that my graphics card runs much hotter when running
games than it does when running the exact same game on Windows.
Neverwinter Nights 1 and World of Warcraft easily hit the upper 90s on
Ubuntu. This is considerably higher than on Windows.

Does anyone know why this happens? Is this an issue of DirectX versus
OpenGL? I know there were problems in past versions of nvidia-settings
that caused it to report temps higher than they really were. Is this
still the case?

Card: EVGA GeForce 6800 Gt
nVidia Driver: 100.14.19

(I previously tried a.c.p.videocards.nvidia with no luck.)