I received my 3 X5650 CPUs and I am not sure what would be the ideal 24/7 voltages including the CPU and qpi/dram.
I have one X5650 that can boot at 4.5 GHz with a 22X multiplier, but it isn't stable at 1.35v for the CPU and 1.31v for qpi. I can go even higher, 4.7 GHz, and it posts, but it's not stable when it boots (@1.35v for CPU and 1.31v for qpi). It doesn't post at 4.8 with. At that same 1.35v for the CPU and 1.31v for qpi, I can get it stable at 4.2 GHz.
I think I could make it go faster and keep it stable by increasing the voltage past 1.35v, but I am a bit leery of doing that.
I've read at a few spots, including the X58 OC guide where it says the CPU shouldn't be pushed past 1.35v for a 32nm Westmere CPU. I've seen screenshots on this thread where people go past 1.4 V. I've also read in this thread that anything above 1.3v will reduce the lifespan of the CPU.
I've tried another X5650 CPU and I can hit 4.79 GHz at 1.33v and 1.31 for QPI and it's been able to go through memtest+ for over 12 hours without any problems. I was able to boot into linux and keep a load of about 20-30% for a few hours without any issues. I will be doing some other tests on it soon.
I haven't tried my last X5650 CPU yet. I wanted to get some guidance on the "best practice" voltages that I should be using going forward since 2 of the CPUs will be going into my home server (and I don't want to damage them by over-volting them).
As an FYI, I am using a Corsair A70 cooler and the temperatures seem to be under control. For the above setup, it idles at 10° above ambient at 4.4 GHz. The MB is an ASUS P6T6 WS Revolution. I haven't checked the temps yet at 100% load.