I'm not well versed in this area but check to make sure the PSU can handle it on your 1,1... I couldn't find anything on the internet about the R9 280X Gaming 3G working on a 1,1 but nobody said it couldn't either... I might just go ahead and get the 6G to put this issue to rest and report back. If anyone has any experience or can help either of us please respond 🙂