>> Getting around 5Mh per x 5 and running at 876 in BFG miner bat file, extra usb fan for cooling.

Same here. Note that hashrate = 5.66 x clockfrequency, so 876x5.66= 5Mh/s (if all cores are working). I had to trim the core voltage a bit more compared to my previous 832Mhz. I tried first 856, then I got a bit more HW errors, then 876 and a lot more HW errors (>> 1%), that gave me an idea how much to change the core voltage pot. Now it is steady at just below 1% error rate.