Based on the data, anything beyond 2.8GHz will take some serious effort. Also, it appears that the 2.2A's have the greatest potential for the extreme frequencies given that they tend to need less voltage as frequency increases. A clear conclusion I made viewing these graphs, is the amazing value of the 1.6A's.
If you really want the upper end frequencies, target the 2.2V vCore range with some impressive cooling capacity.
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