Hi dudes. First Iam sorry for my english And lets go to the problem. I have a big problem when I want overclock my Phenom II X4 955BE C3. With my stock voltage 1,4v in bios (in CPUZ is 1,392v) I can overdrive from 3,2ghz to 3,8 ghz. I always checked frequency via Prime95 small, blend stress test (Temps on each cores are under 50°C- I use Gelid Tranquillo with Enermax Magma fan) and on 3,8ghz Iam playing BF3 for 1 year. Everything OK. Problem start when I rise only CPU vcore by any increment, for example +0,025v. System boots up to Windows, when I start small FFT test in Prime95, temps are still under 50°C, everything is stable. But when I start Blend or large FFT test, prime display ERROR on one core, or I get BSOD. When I play BF3, system crash up to 30 minutes. My RAM speed are 800MHz DDR2 as default, I didnt change their speed. In small FFT test my is stable 4Ghz@1,44v real, and 4,1ghz@1,488v real, but when I run blend or large there is problem. Another test, LINX. I prefer 14000 problem size with 15 run times. Test is without any ERRORS or BSOD. But BF3 crash. I update my bios to the latest version F7B. I changed only multiplier, C1R, CnQ are disable. Is it Mobo problem or my CPU is bad piece to OC. Thanks
3.8ghz is still a good oc for this chip, i was sitting at this speed for a long time with my old 965 C3, you can have 4.0ghz or more if you're lucky but with alot more vcore and heat, don't think the perf gain worth it. 3.8ghz is enough to play BF3, i think.
I solved this problem yesterday. Problem was with DDR2 voltage control. If voltage control was on AUTO, DDR2 real votlage was 1,936v (I used HW info to read voltage), but if I switched voltage control on MANUAL, automatically DDR2 voltage droped down to 1,84v. I had to increase DDR2 voltage by +0,1v and now I have the same DDR voltage like before (1,936v). And this was a problem with stability. And now I can use 4 ghz on 1,472v, and NB frequency is 2600mhz on 1,25v CPU-NB. When I am playing BF3 up to 2h, temperature on CPU is below 50°C. I use Gelid Tranquillo with Enermax magma fan.