Help me OC my E8400

[profJim]

Re: Help me OC my E8400

A general guideline:
VTT should be set at least 0.05 - 0.10 volts lower than CPU Vcore when overclocking.

VTT up to about 1.35 or so is not excessive when your CPU Vcore is 1.40 volts or higher.
Increasing VTT often helps with stability if there are errors when running stress testing programs.
Ideally you'll use the lowest possible VTT voltage setting.

With higher overclocks, MCH Core voltage might need to be bumped a bit higher.

[D-Rock]

Re: Help me OC my E8400

Okay, well I am at work atm. Tonight when I arrive home I will increase Vcore and MCH core. I dont think I will have to worry about the MCH voltage too much at 1.3ish since its watercooled. I will do that and bump vcore up to maybe 1.35v and stress test again overnight with the 9x multi again. If that doesnt help I will raise vtt, and test the bus over again with the gtl voltages to see if thats still stable. Once I get that stable if needed then I will raise the multi again and try again with raised vcore and mch core. It might take between 1 and 5 nights to post back depending on how many stress tests I need to run to get to that point.

Again THANKS for the help. I am learning so much.

[D-Rock]

Re: Help me OC my E8400

Oh and I have been reading that different BIOS revisions affect overclocking performance. I got to 3.8ghz on F9, then went to F11 when I got all the new watercooling parts. Now I see that F12 is out and I was wondering if anyone knows what the differences in the revisions are and if there are overclocking differences. I cant even seem to find a general change log or bios history file. thanks.

[Eek]

Re: Help me OC my E8400

Dont be scared to bump up VTT or PLL, I use 1.59 PLL for 24/7 and no degradation at all (some go as high as 1.75 but I wouldnt do that for 24/7).
If one cores fails it would need more vCore (sometimes up one notch VTT).

[BoombasticSloth]

Re: Help me OC my E8400

I dont think I will have to worry about the MCH voltage too much at 1.3ish since its watercooled.

Remember you are only using 2 sticks of ram. You don't have to raise your MCH voltage that much. When profJim mentioned, "with higher overclocks, MCH Core voltage might need to be bumped a bit higher", that was based on your mch core being at 1.20v. I suspect 1.22v-1.26v, might be good enough for you. YMMV.

If I were you, I would bump the mch core up to 1.22v-1.24v, bump vtt up a step or two, and then bump your vcore up to what you feel comfortable with 1.35v+. Then start bumping your vtt some more. If those don't work, then play with your gtl refs.

All the best.

[profJim]

Re: Help me OC my E8400

^^^^ Good advice.
The voltage ranges in post #20 are in the ballpark for 2x2GB of 1066 memory.
Higher than stock voltages are often required, but it's up to you to find the optimal settings where your system is stable. Generally, MCH Core voltage settings above 1.30 volts are not needed unless you are performing an extreme overclock or pushing your memory speeds well above 1100MHz.