It might work it might not, some have reported problems with using 2.1 cards on a 2.0 board even though the PCIe spec is supposed to be backwards compatible through all versions.
^
Really? I thought that problems only occur on 1.0 board...
You could be right on that (many beers have been consumed here) but either way the PCIe spec was supposed to be backwards compatible through all versions, it just doesn't seem to have worked out that way.
I used a HIS 5670 1gb 2.1pcie card on my 2.0 ASUS 890GX mobo and it worked fine so I guess Im the best answer for this topic but thanks for helping guys.