hi solar this is what works for me
For those interested in Extreme Overclocking
When Extreme Cooling the EVGA Classified or regular board, I usually have a set fix of steps.
My Observation/Theory:
The i7 CPUs are kinda different from the LGA775 CPUs when extreme cooling them. Temperature makes a huge difference in the amount of current / speed with which current flows through the CPU. The CPU does not like it when it’s comfortable level is passed. The higher the Voltage the faster the current flows. The cooler the temperature, the faster the current flows. The more loaded the CPU, the more the amount of current flows.
So you may observe instances such as these:
Your CPU is stable at 4.6GHz 1.8v VCore at -20C but unstable at 4.6GHz 1.8v VCore at -100C. (Though you will be able to run higher Vcore when cold on EVGA X58s compared to other X58s.)
Your CPU is stable sitting in Desktop at 5GHz -130C 1.6v but unstable running through CPU Tests and you need to run warmer than -120C to pass CPU Tests or lower VCore to 1.55v to pass CPU Tests at -130C. (CPU Tests puts a lot of current through your CPU and the colder the temperature/the higher the voltage that faster it flows – till it surpasses the comfort zone)
Your CPU is not stable at -120C with 3.6GHz Uncore but stable at -120C with 4.5GHz Uncore. (Higher Uncore warms the CPU so that the actual CPU Die is warmer)
Why not tape up some of the VCC (VCore) or VSS (Ground) pins of the CPU to lower this effect? That would be like adding weights to a Race car so it slows down and doesn’t flip at corners – you cover up a hole and open another.
So in effect it is a situation one has to handle and the trick is to find the optimum sweetspot combination of temperature, Frequencies (CPU Core, Uncore, Memory) and voltage.
So a typical Extreme Cooling session for me is like this:
Flip the jumper X-Cool to the 2-3 position, or for the regular board I choose Extreme Cooling Mode 2.
http://g.imagehost.org/0714/1_15.jpg
Then I boot up and start setting settings. (This typically happens for me before I go lower than -50C on the CPU).
I set the voltages (when Extreme Overclocking/Cooling):
http://g.imagehost.org/0205/5_6.jpg
I also set the Memory Timings and Ratios.
I set 25x Multiplier (as I’m using 965XE).
I calculate the target Hostclock I have in mind (For eg, I’m aiming to run 29 x 169MHz -> 4900 MHz I tend to stick to 29x) so I key in 169 MHz here.
I set the Uncore Multiplier of my target.
Note: I tend to set these before CPU hits lower than -40/-50C. I always boot at 25x CPU Multiplier and 1.45 – 1.5v VCore. I always boot at or close to the Host Clock I wanna run.
Then I go into OS and use ELEET or the enclosed ECP Accessory to fine tune CPU VCore (typically the sweet spot ends up around 1.55 - 1.7v) and CPU Multiplier as temperatures drop further. When I reboot to go into the BIOS henceforth, I only adjust DIMM Voltage, or Host Clock, and not options that require a shutdown and poweron again (Such as Memory Ratio/Uncore Ratio), especially when my CPU is @ -100C.
This is what works best for me.
and your all free to do so too
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Originally Posted by pa9797
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