Just installed the Windows 8 international x64 driver on an older asus core duo notebook with Gforce 9M series dedicated graphics. The previous 'loaner' driver from win7 showed a paltry 2.1 on Windows 8 WEI, Desktop/Aero performance. Removed that old pile and installed new, reran the assessment and now showing 3.4.
That's a pretty good score for the age of the system. My thinkpad w/shared ATI 6310 does a 4.0 with the latest ATI Catalyst 12.6

nicely done Nvidia.