Just to add that apparently the 32EFI is a limiting factor in the choice of GFX cards for the 1,1 Mac Pro. Currently newer ATI cards seem to work unlike their Nvidia counterparts. However, I believe it's a matter of time before ATI drops EFI32 support. As a side point, the fact that the 1,1 Mac Pro doesn't have PCI 2.0 hurts its viability in future video upgrades as well.