Reasonable OC for E6750?

[pscout]

I have found that leaving vcore on auto is going to most likely result in much higher vc than necessary.

The bios is gonna assume worst case for your cpu and give it more volts than it really needs.

Much better to set it manually, and bump it by the minimum necessary to get to the next oc. It can be time consuming but in the end you get the best oc/vc balance that way.

I fold on all my oc'ed rigs, and have found through measurement of power consumption that getting ~ 3.3 ghz on current stepping quads at <= 1.375V is about optimum for me on the better chips, and to ~ 3.1-3.2 ghz on average chips. I would expect the current DC's like your 6750's to go a bit higher on similar VC or lower depending how good each chip is.

Cooling will affect this some as well but is likely less of an issue if you are not running apps like folding 724 since it drives ~ 100% cpu.

High end GPU heat production can have a big impact since even if they exhaust heat outside your case, the backsides of the cards are usually adjacent to the NB and can get quite toasty. Good airflow and/or supplemental NB cooling will compensate.

AUTO vCore setting on Asus boards will default to ~1.325 iirc.

CPU-Z will read your vCore at about 1.55 at this setting. It has nothing to do with the volts actually going through the CPU.

If you want the voltage to be higher than stock you're going to have to set it that way yourself.

As for the temps, I suggest water cooling ;)

[ert7849]

Actually that 1.55 reading I got wasn't from cpu-z, it was from asus pc-probe (software included with my mobo). Well, anyway, I went into the bios and changed it from auto to 1.375 and it is stable under orthos prime 2004 and temps in the upper 50's. So I figure this is good enough for me. Thanks for the help guys! ;)

[pscout]

Originally Posted by Misoprostol

AUTO vCore setting on Asus boards will default to ~1.325 iirc.

CPU-Z will read your vCore at about 1.55 at this setting. It has nothing to do with the volts actually going through the CPU.

I don't use auto but I have tried it on a few mobos and have found that asus/gigabyte bios will raise the vc as you raise the fsb. Behaviour probably depends on bios level and mobo but i haven't 'tested it on all my rigs. At stock fsb, I think it will set VC = VID for the cpu.

Latest cpu-z (> V 1.41) seems to read c2Q vc consistently with speedfan and asus probe or easytune on giga mobos. Older versions were wrong on newest cpu's/mobos.

[Ed_JS]

On my Asus P5K-E, the VC increases with the FSB when on AUTO. I have SpeedStep enable, & noticed that on Auto, VC is lowered when the CPU is throttled back to x6 multiplier as well.

And the MOBO is setting VC higher than needed in my case. At my current 8x425 (3.4 GHz), auto will set VC to around 1.5, even though the setup is stable at 1.35. On the higher volts, I am noticing at least 5-6C higher temp readings.

[pscout]

Originally Posted by Ed_JS

On my Asus P5K-E, the VC increases with the FSB when on AUTO. I have SpeedStep enable, & noticed that on Auto, VC is lowered when the CPU is throttled back to x6 multiplier as well.

And the MOBO is setting VC higher than needed in my case. At my current 8x425 (3.4 GHz), auto will set VC to around 1.5, even though the setup is stable at 1.35. On the higher volts, I am noticing at least 5-6C higher temp readings.

That is a very nice oc for 1.35V - nice chip