All DFI boards that i know of have the DOS Skew control settings, but all that does is handle EMI interference generated by noise from voltage going through the board. Way way back when in the before pentium era that setting actually did something. With better filtered power supplies and better manufacturing process for motherboards, there isnt a need for this setting any more. I highly doubt that the ACC aforementioned is this skew control. Hooking pins up to a south bridge, to me that sounds more like bull since the south bridge functions as the link to the lower buses on the board the pci slots, pcie slots, then the north bridge is the traffic cop that directs things from the upper buses and built in connectors to the back of the board. With AMD the memory controller is on the chip so the NB all it does is regulate traffic of data from inputs to the cpu and outputs to the SB chipset.

I really dont see how hooking up 6 unused pins to a south bridge chipset did anything. I cant blame AMD for wanting to keep this newfound thing quiet, but maybe it is something that is enabled in the bios and they tied it to boards with the SB750 chipset to sell more motherboards. I think it is great that ACC gives good performance boosts in overclocks, but i think they are feeding a load of crap to the general public that has no idea how the internals of a computer works. Maybe later on they will release and disclose what exactly is the real cause of making the boards with SB750s oc so much better.