Any motherboard with PCI-E slots v1.1 or newer would work. With PCI-E slots smaller than a x16 slot you need to use risers, preferably powered risers. Also older motherboards with PCI slots are NOT compatible with PCI-E cards or risers.
First of all, pci-e not pci, my bad.
I have a processor that only supports 20 pcie lanes. That means if i had to install 2 GPUs, I'd have to run them both on x8. What I'm curious about is is the performance throttle bearable enough for me not to notice it?