Core i7/X58 Overclocking Thread

[The-Fox]

In the table below I think max qpi v is vtta and vttd -

Yes, the spec claims max voltage of 1.35v to the Vtt analog or digital portions make no difference according to the spec.
According to the spec, the analog and digital domains of the QPI should be fed by the same voltage.
I wonder if different voltages to the Analog domain and digital domain of the QPI can help to achieve higher QPI clocks.

That crappy IMC theory certainly holds true for my 940. I can run prime, linx etc fully stable at 23x192 (4,4Ghz) with 6x ram mult, but even the 8x is no go. Boots into Windows but freezes with an evil Bluescreen after 10-20 minutes of prime. That is running 3x2gb with the most relaxed timings and subtimings possible, and 2T. Also tried up to 1,6V VTT to no avail. Uncore speed seems fine, I am currently running 6x dram and 20x uncore mult (3,8xxGhz uncore) so it's not that. It really has a crappy IMC.
Furthermore I had no trouble running DDR3-2000 with my previous 3838A 920 with the same mobo and rams, so I can rule them out. I guess I got a good CPU for high Mhz (does 4Ghz at 1,3V) but it has the crappiest IMC ever.

Unless it will run the mem better using other CPU multipliers - anyone compared that yet? Or maybe it'll simply need more Vcore to do it, even though that is kinda unlogical to me. Penny for your thoughts guys...

I kind of have the same issue only at different speeds.
I can run my CPU (x21 multi) with DDR 1800-1850 Mhz-> bClk 180-185Mhz with DRAM multi x10 benchable.
But it won't do even lower dram speeds at high CPU speeds, I couldn't pass 215 bClk with x21 CPU multi and x8 Dram multi which results in 1720 Mhz.
I tried to relax timings and raise QPI/VTT voltage to a high degree of 1.65v but none of this helped.
It was very frustrating as I could run higher CPU speeds (221blck x 21 CPU multi) at x6 Dram benchable.

I concluded that my IMC just can't run high DRAM speeds at high CPU speeds.