It depends on your cpu, run prime 95 for 12 hours overnight, if no errors, lower voltage or increase your bclk by 5-10 each time and run prime overnight to see if stable. If stable at your wanted clock speed, lower your cpu voltage lower a bit and lower dram voltage to under 1.65v
I increased bclk to 182 and cpu voltage to 1.25v to overclock @4.0ghz. I tried 1.20 and I was getting overclock failed messages and windows wouldn't boot. I tried 1.3v and got the same. I went to 1.25v and it booted and I ran prime95 for two hours with temperatures from 76c-80c. Pretty hot.
Should I keep trying to lower the cpu voltage in increments now? I'd like to get temps under 76c. I purchased two Scyth Gentle Typhoon fans to set up a push-pull config on my Corsair H50 radiator. I'd imagine this should hopefully lower temps by 5c. If I could get down to low seventies with a 4.0ghz clock speed that'd be awesome.
Are there any other settings i need to adjust? I changed the QPI to 1.3v.
Also, I can't set my dram frequency to 1600mhz any more. This relates to the blck change I suppose but how do I get it running at proper speed? I think I have it at 1480mhz or something right now. Next option is 1800mhz so should I choose that? Couldn't find a manual entry.