I currently have a Gaming Rig with the following Specs:
16GB DDR3 RAM
128GB OCZ SSD (I know, it failed on me last night)
1TB Seagate HDD
Corsair TX850M (First revision I believe)
LG DVD Reader/Writer
Powercolour R9 280x
I'd like to know if this setup will be able to run another R9 280X. Will the PSU be able to handle all of this, plus another R9 280X?
I think you will be fine. Those power supplies are really good.