The Source  for Mac Performance News and Reviews

Q:  Can I use a PC Nvidia card in a Mac?

A:  If you have a PC to use to flash the card (not all models will work with the mac rom - the GF3 Ti and GF4MX and Ti cards will not normally flash with a Mac rom unless there are card mods done) - see Mac rom site with nvflash utility at
http://www.cybercoment.com/macgeforce.htm

(previous info follows from several years ago)
Since there's no mac rom available for nvidia FX cards (the only mac FX card to date is the low end FX5200 model that shipped in G5s starting in August 2003) there's no information on any trying to flash one of the latest Nvidia FX PC cards.

Based on reports in the main site Forums - no PC GeForce4 Titanium card or GeForce4MX card works with the Mac roms from those cards. (There have been several reports of failures to work from readers in the main site forums Video card section since spring 2002. One reader in 2004 said someone found a way to modify the GF3 Ti cards to accept a flash, but no details on the mods - he's was selling them on ebay.)

[previous info follows]

For comments on flashing PC Geforce3 cards for use with macs, see this article. (Older article using original GF3 series - Note that no GeForce3 Ti series cards work with the Mac GF3 ROM based on reader reports of failures.)

For info on using PC GeForce2MX cards in Macs, see this article and the main site discussion forums for reader reports. (See the updated notes on G4 firmware updates and read the discussion forum reports for the most up to date reports.) Generally the PCI versions of the GF2MX have not had good success (unless I missed a report, most noted problems with PCI versions, perhaps since the Mac GF2MX roms are from an AGP card.)

As noted in the interviews/articles at the main site - Nvidia does plan to have mac support in all future Graphics chips, but so far there have been no retail Nvidia cards for Mac available (only the BTO Apple store options and cards listed at the Apple store Accessories page).