This one is very tricky atm. With ASUS board I'm able to boot up to FCLK 2000MHz but it's super unstable as WHEA 19 warnings appears even at idle and performance is lower than with 1900FCLK.
With 1900FCLK everything seems super stable, Prime95, y-cruncher, TM5, Cinebench can go on for hours, no crash. Games, hours of gaming and no crash. But.. once in a while under heavy load (mostly multicore synthetic benchmarks) whea 19 bus interconnect warning is recorded.
So far I could get rid of these warnings it in two ways:
One is setting FCLK to 1600, and there's no middle ground here, 1633 and eventually WHEA will appear, so I think it's still an early BIOS issue rather than chip quality.
Second way to get rid of them is to enable ECO mode, I just discovered it yesterday so I need to play around with it to check if maybe just lowering CPU power a bit is enough. With ECO, you loose around 10% of multicore performance, hardly any single core (and game) performance, and temps are like 20 to 30 lower. I could run Prime95 with AVX enabled an hour with not a single WHEA recorded, previously it was a matter of minutes.
For MSI boards my friend said that with newest BIOS your FCLK is going to be stable, or you wont boot at all, but their wall is more around 1900MHz, while with older bioses they could boot with up to 2033 but anything above 1600 was unstable.