Quote Originally Posted by dejanh View Post
Question, is anybody having problems clocking Uncore independently on D0 chips only using the Classified? I'm trying to figure out if there is a problem with the boards or BIOS or something to do with the D0 chips. Basically, Uncore can only be clocked 2:1 to DRAM or just a bit above (say +1x multiplier). An example would be if DRAM was at 1600MHz Uncore is okay if it is at 3200MHz, or 3400Mhz, but 3600MHz will cause an infinite F3/68 loop at boot and the system will not post. However, if you increase the DRAM speed to say 1700MHz, then 3400MHz (16x Uncore) is okay and so is just over 3600MHz (17x Uncore) but 18x Uncore or higher is not. If you go to faster DRAM yet, say 2000MHz, then you can set the Uncore to 20x or 21x but not 22x.
I just tried this on my 759 Classified. With Ram at 1600 Uncore at 18 worked OK(3600). Moving Uncore up to 19(3800) still booted but frequency was moved back to 3600 as reported by Eleet. I boosted Uncore voltage from 1.4 to 1.5 and still got the same results.