Legit Reviews invested the significant amount of money it takes to build a QuadFX system, and overclocked it as far as they could.  At 3.1GHz the system leveled out, so that is the speed the used in comparative benchmarks with the QX6700.  Even though the performance did increase, can it possibly reduce the performance gap, especially when you consider the $200 difference in CPU price as well as the motherboard.
“Legit Reviews recently looked at the top AMD QuadFX platform running FX-74 processors and was left wondering what a pair of FX-70 processors could do for less money. We got in the ‘budget’ QuadFX processors and did what any end user would do once they got them – overclock them to the max. We turned these 2.6GHz processors into 3.1GHz beasts, but was it enough for them to catch up to the Intel QX6700?”

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