I hope you see this over a year later...
I am indeed having similar driver issues with this card.
As a starving artist type, I buy evil bay specials and acquired a MacPro1,1 2.66 "quad" with a working stock GeForce 7300GT however, my G5 that's only a year older experienced graphics related issues which prompted me to at least "upgrade" to an Intel-based Mac. At least I can update Safari now. Yay. : \
So now I have a MacPro1,1 "original" and bought a used (of course) FX 4500 for it.
I figured that I'd swap out my cards and keep the GeForce as a spare. That's where my problems started.
nVidia does not have drivers available for Mac for the Quadro FX 4500 despite every Apple related community thread pointing to that card as an officially compatible upgrade/special order card which is not only totally confusing but IMHO quite asinine.
My question to you is this: will I have to take the arduous path of reinstalling my truckload of music apps, yea, even my entire system if I "downgrade" back to 10.6.3 from my retail disc? I have the original 10.4.7 disc as well. (The guy kept everything!) Does the 10.6.3 disc have the proper drivers that may be destroyed when Software Update brings the system up to .6.8?
This FX 4500 is recoginzed by System Profiler as a "G70 Board- q348-0" with nvidia listed as vendor but won't display my system but only lights up the displays with the blue-grey background and no Apple or "booting" indicator. That's when the Quadro is the only card in the machine.
However, when the oem GeForce card is sitting next to it in slot 2 and both DVI cables are in the Quadro, I get both displays but the "main" display is on the second and vice versa and the Quadro's fan is slow enough to almost count the fan blades as it turns despite Expansion Slot Utility claiming it's running at full speed and again, unless I have BOTH cards installed, I get nothing but empty blue-grey screens.
I did not mess around with any previous drivers and the ones I downed from nVidia are quite wrong as I've discovered. I downed the "Quadro 4000 for Mac" drivers assuming that it was a 4000 *SERIES* similar to the PC counterpart, for example, when you need a printer driver or something. Silly me.
I'll take this to the community now to see if I have a paperweight or if at least I can flip it.
Thanks Peace Blessings