Not a lot is known about the top end, R9 290X, except that it will be the first gaming GPU to cross 5 TeraFLOPs of compute performance. To put that into comparison, the GeForce Titan has a theoretical maximum of 4.5 TeraFLOPs."
Any major computer upgrade generally requires a full software reinstall too. No so if you heed the advice in the guide to Upgrading a Motherboard without Reinstalling. PCSTATS Tips