Video card - how do I determine compatibility?

[gnome]

Quote from slamminsteve:

Yep, my PCIE x16 is occupied by the ATI card so I can replace that with the 285 and get the 280 as my second. And I'll make sure to look it says PCI for hte latter.

Thanks again for everyone's help/feedback.

FYI - It's this description, and others, on eBay that was confusing me:

Oops, my bad. The 280 DID come in a PCIE1x16 for a little while before they made 285's... sorry about confusing you.

The 280 AGP and 280 PCIEx16 are no longer in production... only the 280 PCI, in the "280" model.... the other 280's can usually be found on eBay, however.