i5 750 overclock, my 1st attempt (noob alert!)

I have the same motherboard, CPU and similar ram as you (ozc reaper 1600mhz) mine too needs 1.30625 VTT at 200 BLK to be stable. Your on the right track. My ram will run at 6-8-6-26 at only 1.4V though :)

Running mine at 3.8G 1.24375
 
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Can't fault your methods - you'll find optimum settings eventually. I think generally most OCs are 'easier' using maximum multiplier and keeping the bclk down, so you're right to come down to 200. For example many people achieve their 4GHz with 191x21. My mobo can manage 20x200 which is ideal and lets me run my ram at full rated speed. I find i needed a little boost of CPU PLL. My settings are as follows (some may be named slightly differently to yours as my mobo is gigabyte).

20x200
mem multi x8
qpi ratio x32
pci clock 100
ram 9 9 9 24 (XMP disabled mem setup manual with performance enhance 'turbo')

vcore 1.375 in BIOS (CPUZ shows 1.36 at idle and 1.392 load with LLC on level 2)
qpi vtt 1.3
pch 1.1
cpu pll 1.9
ram 1.66

cpu and pci clock drive both 900mv

As you can see my chip isn't the best one to come out of the factory and I need pretty high volts for my 4GHz, but it's all within spec so not concerned.

I personally wouldn't worry too much about hitting 80 stress testing - you're still 20 degrees from tjmax and you wont reach that in real use anyway. Having said that you might want to check how it does in IBT - I find IBT at least 5 degrees hotter than Prime. I just hit 80 in IBT at 4GHz with my H50.
 
Thanks for the help, top advice.

Well anyhow i strived on to find what was the lowest vcore i could run @ 3.8ghz. Found 1.25625 vcore with 1.30625vtt to be stable and give nice temps, max temps 74*c in prime over an 8hour run. And its idling now around 35*c. So i'm all happy on that.

Onto the ram situation, Currently using blck 200 x 19 to get 3.8ghz, But my ram multiplier has to be x6, Any higher and it causes my system to crash on a prime95 run after a couple of mins.
Although its running at 1204mhz i managed to get the timmings down to 7-7-7-20.
So is there a lot of point for me trying to get 1600mhz out of it? Would i notice it on benchmarks?
I do a lot of gaming, and compressing / extracting files.

But i'm very happy withmyself now that i have found a good overclock with nice temps and not too high volts. Bearing in mind my cpu is cooler by a cheap air cooler, its doing well ! :)

Thanks a lot for your help again guys, its been great.
 
3.8ghz at 1.25625vcore is pretty good going. You probably find you could get 4.2ghz from it, but you'd need a better cooler to keep the temps down.

As for the memory, have a read through this :

http://www.tomshardware.com/reviews/core-i7-870-1156,2482.html

If you're desperate for the 2-5% performance difference, or just want to tweak your pc when you have some spare time on your hands, then go for it. Just take some pics / note down your current stable ram settings / timings before you tweak anything :)
 
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