For the 990X vs 980X argument, my 990X does 4.5GHz HT on @ 1.336v load, its in the 4.5GHz LinX thread for reference. A decent 990X appears to be no better than a decent 980X, but the best of the best were the late model gem batch 980X's Ive seen. Better than my 990X by maybe 0.03v for 4.5GHz.