from the motherboard vendor itself the first link i posted. on the specification tab it brings up a sheet of the motherboard spec you look under onbord slots.
1 x PCIe 2.0 x16
1 x PCIe 2.0 x1
1 x PCI
the top one is the video card slot it the older 2.0 slot at 16x speed. any newer gpu will run in the older 2.0 slots they just wont be able to run at newer pci 3.0 speed. but with the pci standard most video cards out there now cant max out the pci 2.0 speed yet.
with video card every newer mb from a few years ago uses the same slot cards. the older agp was killed off 4 or 5 years ago they dont make any new cards in agp now. what you have to be care full is the size and brand of your power supply. to low of wattage and your pc wont turn on with some of these high end cards. a no name cheap power supply when put under load may fail or pop.