We don’t support that in a Mac Pro!!
April 25, 2008 Leave a comment
I have two graphics cards in my 1st generation MacPro which allow me to drive three monitors. I originally bought the machine two NVIDIA GeForce 7300 GT video cards because the two other choices were not really good choices (one was very expensive, and the other was a card which suffered from overheating). At the time the NVIDIA GeForce 7300 GT video card was considered respectable, which is another way of saying that it worked fine is a little pokey and was going to be EOLed momentarily.
Last week Apple released an NVIDIA GeForce 8800 GT video card upgrade for the 1st generation MacPro and I bought myself two to replace the two NVIDIA GeForce 7300 GT video cards. The card originally released only works in the 2nd generation MacPro (PCI express v.1 vs. v.2 issue.)
One of the NVIDIA GeForce 8800 GT video cards died after one day, the MacPro just did not “see” it anymore. The machine would boot fine but never detected the card, and the fan on the card was continually spinning at full speed, usually a good sign of a bad problem.
I called Apple and they told me that this was not a supported configuration. They first told me that this was a power draw issue which seems odd since the card is rated at 110W and Apple claims that the PCI express bus supports “300W for up to four PCI Express graphics cards”. Then they told me that it had to do with PCI express lanes, yeah right… what next, Aperture does not use the GPU to help with photo processing… oh wait, they did not know that either…
It came down to this, it just wasn’t a supported configuration. I had no choice but to replace the dead NVIDIA GeForce 8800 GT video card with one of the NVIDIA GeForce 7300 GT video cards.
One thing I learnt is that if you have two video cards in a 1st generation MacPro you should put them in slots 1 and 4 to get the best bandwidth out of the cards. You can also use a utility called “Expansion Slot Utility” which is located in “/System/Library/Core Services/”. This utility allows you some control on how the PCIe lanes are apportioned between the PCI cards in your MacPro. This does not apply to the 2nd generation MacPro though, that generation manages that automatically (what did you expect, they are 2nd generation!!)