Figuring out PCI-e version on motherboard

So I'm thinking of upgrading my graphics card but my motherboard is getting a little old. From what I've read there aren't any problems plugging a PCI-e 2.0 card in a 1.1 or 1.0a slot, but there could be issues with a 1.0 slot. The problem is I'm not sure what version my mobo has. On its spec page (http://usa.asus.com/products.aspx?l1=3&l2=11&l3=331&l4=0&model=1311&modelmenu=2) it just says "PCI-E x16". Does anybody know what version it might be (or maybe can figure out something something I can't from looking at the spec page)?

I post this in the graphics section because I'd also like to ask, if it is 1.1 or 1.0a, do you think a Radeon HD 4770 will max out the bandwidth? Most topics I've read say that most cards will work just fine on the old PCI-e versions, but some of the topics are kinda dated and I just want to make sure.

I'd really appreciate any input you guys have.

invisik is right, you can run a 4770 on the PCIe 1.0 slot, no problem.

Good luck with your HD 4770