Ich hatte genau denselben Fehler.
Das hab ich vom 3DMark Support bekommen
"Hi,
There has been some reports that the version 21.8x of the Detonator XP drivers cause some anomalities with 3DMark2001. It seems that
the drivers don't free up any vertexbuffers and this causes the "outofmemory" error. This error should have been corrected in later
driverreleases (23.11 and newer)."
Neue Treiber installieren =P