AMD Phenom II X6 1090T Overclock

0sprey

Honorable
Aug 27, 2013
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10,510
CPU: AMD Phenom II X6 1090T
GPU: AMD Radeon HD 7850
PSU: Corsair Builder Series CX 600 Watt ATX/EPS
Motherboad: DELL 0NWWY0

I am overclocking my CPU and it is extremely stable at 3800MHz running at 1.375 V. I stress tested it for 1 hour and the maximum temperature that I got was 55C, with 0 errors.
The moment I turned it up to 4000MHz my system crashed. I didn't even get the chance to stress test, it just crashed. Other people's overclocks that I have looked at said that they were able to get this same processor up to 4.0GHz at 1.375 V with 0 errors and around 49-55 C.

The question that I have is what would cause an instant blue screen? Were my volts not high enough? The second question is that I have read that the best overclock for AMD is to overclock the Northbridge, how does one go about doing that?

Note: that my BIOS is weird where I can't change the CPU settings in the BIOS but instead had to get AMD Overdrive to do so. Also cool n' quite is turned off.