This is probably an oft-discussed topic but I can’t find it in the groups.
Initially I installed the nVidia driver from the CUDA web page, then I reinstalled a newer driver from the general nVidia page:
cudadriver_2.3_winxp_32_190.38_general.exe: processing times are great, with little variations from iteration to iteration.
195.62_desktop_winxp_32bit_english_whql.exe: processing times are poor, sometimes with wild variations from iteration to iteration.
Is this expected? That’s going to be a maintenance issue because video drivers are easily updated by anyone, but the relationship with GPU performance might not be obvious.