reading lots of motherboard reviews, found that:
AMD 790GX / SB750 chipset is better for stock 3D graphics.
BUT....
Nvidia nForce 780a has much better USB2.0 performance measured with HDtach.
overclock is other story...
also that 780i beats some intel chips too: p35 and x35 in USB2.0 performance.
also that MB circuit design change a bit those numbers, diferent MB manufacturers with same chipset.!
nvidia 8300 chip similar USB2.0 performance as nForce 750i, 21.5MB/s
the SB600 gives in one test 21.5MB/s in other 28MB/s = strange.
the best USB2.0 chips have tranfer rate of 35MB/s measured with simplysoftware HDTach3.0.4.
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