Looking at the congregated results here with DS5... I'd say GBT has a major BIOS problem. I know they had trouble with 1066 for a while, so before you decide what is stable or not, I'd try testing 800 mode, stock NB, stock HT and 1x2GB instead of more than 1x2GB if you use that. Many times moving HT 1MHz seems to make NB/CPU very unstable unless you add voltage to the NB - a trend with the 9850 unlike B2

Also beware, DS5 I tested a long while back was overvolting especially under load - if stock was 1.25v then under load it overvolted to 1.280v. The feature carried over to the 780G and 740G offerings too.

Hows AOD compatibility coming along?
Anyone tried the AutoClock and Stability tests at/for high MHz?

I'd test some things on it but I don't have a DS5 here.