Is a PCI-e 2.1 Graphics card compatible with a motherboard that has PCI-e 2.0 slots? I'm hoping to buy a new graphics card (Radeon HD 5670 thanks to jaguarskx, delluser1 and cronos177 for some very good advice). Anyways at the moment the different models I'm looking at for this card either require PCI-e 2.0 or PCI-e 2.1. My PC is a Dell Dimension 9150 but I'm not sure what type of PCI-e slots it has. Will it matter? Will a card that uses 2.1 work on a 2.0 system?
I would have said no (or actually, not likely) if I had know it were a 945P 1.x board. Especially if Dell hasn't offered a BIOS update for it within the last 2 or 3 years. But, that info wasn't offered, nor was it the question asked
As a 1.x board, then you can forget about anything AMD unless you go back to the 4000-series (or older) cards. Every 5000-series and 6000-series card is PCIe 2.1. Do not be fooled by one mislabeled as 2.0, because it is actually 2.1.