Switched to low-end watercooling, slightly better results... Using a CoolerMaster Aquagate (the big one, not the minis).

Might have been a heat issue - the CNPS9500 kind of sucks for the price.

2600 is now stable at 1.575v according to dual SuperPI 32M, etc. Prime still nowhere close. I have not had luck with Prime in a LONG time though, so I'll trust 3DMark05 and SuperPi.

Still a crappy chip, IMHO. 55C load also sucks.