PCI Express 2.0 Video card on old motherboard?

Hey everyone. I have an Intel 945PSN motherboard, which has a PCI Express slot for the video card. The slot is described in the documentation as being "PCI Express x16". Nowhere does the documentation describe PCI Express 2.0. In that slot, I have installed an ATI 3870x2 dual core graphics card, which uses PCI Express 2.0. Are there any potential issues when connecting a PCI Express 2.0 graphics card to a motherboard that was likely manufactured before there was a PCI Express 2.0 standard, or is the difference purely firmware or internal to the card itself?

2.0 and 1.0 are backward compatible, it shouldn't be a problem. You would lose some performance though.

The performance loss is probably not noticable, if it even exists.

There have been comparisons between SLI on 2 x PCIe 2.0 16x vs SLI on 2 x PCIe 2.0 8x and the performance difference is barely noticable. PCIe 2.0 8x has the same bandwidth as PCIe 1.x 16x.

Toms hardware only listed maybe a 20% max increase in performance with the pci express 2.0 standard. I wouldnt worry about it, Im running a saphire 3870 x2 on my desktop on a gigabyte m-61p-s3 motherboard that only has pci express 1.0 standards, and I tested it on my computer and on my best friends ASUS board that does support pci express 2.0 standards, using the same processor and only 2 gigs more of ram, and I achieved roughly the exact same 3dmark06 score. I think there was less then a 100 point difference. what Id be more concerned about is whether your PSU can handle it, that card is power hungry it fried my first PSU rather fast. but if you got a PSU I doubt the pci express 1.0 will hurt you any at all.