What does the QPI link do exactly?

[andysim 0]

What does the QPI Link do? Ive googled it but its a bit vague so I though I would ask here. I looked in my Bios and it in auto mode which shows as 5.7. It has 36 .44 and 48 settings Im just wondering if its worth setting it at one of these or just leaving it at auto. AIDA64 is reporting it at 3300Mhz and it does not change.I have also bumped up my CPU to 3.6ghz (44c idle 68c in Prime95 8xthread) and its very stable, but knocking it up to 3.86ghz there is an annoying high pitch whine (its not the fans) thats only just audiuble but is that a sign that its not happy? It sounds like one of those cheap dog whistles that no one is supposed to be able to hear but can.

[Bob Scott 7,720]

What does the QPI Link do? Ive googled it but its a bit vague so I though I would ask here. I looked in my Bios and it in auto mode which shows as 5.7. It has 36 .44 and 48 settings Im just wondering if its worth setting it at one of these or just leaving it at auto. AIDA64 is reporting it at 3300Mhz and it does not change.I have also bumped up my CPU to 3.6ghz (44c idle 68c in Prime95 8xthread) and its very stable, but knocking it up to 3.86ghz there is an annoying high pitch whine (its not the fans) thats only just audiuble but is that a sign that its not happy? It sounds like one of those cheap dog whistles that no one is supposed to be able to hear but can.

The QPI is the bidirectional high-speed bus that connects the CPU to the X58 I/O Hub (IOH) on single-CPU i7 machines. On multi-CPU machines, the QPI is also used to connect the CPUs together. Basically, everything except your RAM communicates with the CPU via the QPI connection to the IOH. Leaving it on auto is generally OK, as an FS machine isn't going to saturate the link.As to the whistling, I'd suspect something in either the PSU or the power regulation on the motherboard. If the BIOS allows you to change the voltage regulator PWM frequency, you might try that.