Originally Posted by patricksiglin
You might be able to do 4ghz at 1.425. I got to 3.9 on stock and had to raise it to 1.425 for 4ghz 1.475 for 4.1ghz and 1.5 for 4.2ghz. If you have a decent cooler this should not be a problem with this chip. I currently run mine 24/7 @ 4.1ghz.
Yup. The lack of load line calibration on the Gigabyte FXA ud series, and subsequent voltage fluctuations that result, tell me this:
1.400v @ 4.0ghz is the minimum to get my system to boot.
1.425v @ 4.0ghz will boot into windows, and do things like web browsing. It will not pass prime and it will crash while gaming. At 1.425v, with he lack of LLC on the gigabyte board, I push up to 1.475v while running prime95.
1.450v @ 4.0ghz I can always boot into windows, can run games for a while (will always eventually crash) and cannot pass prime. The max voltage the CPU draws is still 1.475v.
1.475v @ 4.0ghz instead pushes to 1.499v under prime95 load -- and this allows me to pass.
I'm guessing this basically means that I need 1.475 MINIMUM to be stable at 4.0ghz and really should be @ 1.5v.
For this reason I leave my 24/7 oc @ 3.8ghz CPU, 2800mhz NB, 1600mhz RAM. This is stable at just 1.375v and with the....current state...of bulldozer it looks like I'll be keeping my 1100T for awhile and not upgrading til the FINAL revision of the FINAL AM3+ compatible CPU is released.