I7 875k overclock help

[cory1234]

Whats up guys?

I have my i7 875k overclocked to 3.7ghz for the summer. (1.168v, 1.21vtt, 50 linx runs/ 5 hours prime95) I wanted to try something I have never done before; using the speedstep/c states to reduce my multiplier during idle.

My problem: When I enable those features the voltage drops in idle, but the multiplier does not. It isn't stable when my computer is at idle @ 3.7ghz with .9v . Does anyone know what I'm doing wrong? Is there a way to disable some of the c states so the voltage doesn't drop as much? <--- I wouldn't have to do that if I could figure out how to get the multiplier to drop during idle.

Thanks.

 

[wolfram23]

It might be C6 causing instability as it truely shuts down a core. You can try setting the limit to C3 and see if it helps.

Other "stability" features are turning off spread spectrum, and allowing a higher CPU amplituded (try 900 or 1000mV). Might want to try pinpointing which feature is causing the issue by only turning one on at a time. Say, first EIST... test... C1E... test... C States (Auto/C6) - and if that's the issue, try C3.

 

[cory1234]

It might be C6 causing instability as it truely shuts down a core. You can try setting the limit to C3 and see if it helps.

Other "stability" features are turning off spread spectrum, and allowing a higher CPU amplituded (try 900 or 1000mV). Might want to try pinpointing which feature is causing the issue by only turning one on at a time. Say, first EIST... test... C1E... test... C States (Auto/C6) - and if that's the issue, try C3.

Yea, I already tried turning off 6. It seems that speedstep and the cstates are doing exactly the same thing? If I disable one nothing changes.

 

[wolfram23]

Well technically eist is for changing the multiplier and also I believe for slight bclk changes whiltnc states cut or at least reduce voltage to cores. You need both for turbo boost. They're good features to have on but I guess not if they're causing crashes. I think you should be able to tell that c states is working if you watch your idle power in hwmonitor.

 

[Ahwayzcool]

Whats up guys?

I have my i7 875k overclocked to 3.7ghz for the summer. (1.168v, 1.21vtt, 50 linx runs/ 5 hours prime95) I wanted to try something I have never done before; using the speedstep/c states to reduce my multiplier during idle.

My problem: When I enable those features the voltage drops in idle, but the multiplier does not. It isn't stable when my computer is at idle @ 3.7ghz with .9v . Does anyone know what I'm doing wrong? Is there a way to disable some of the c states so the voltage doesn't drop as much? <--- I wouldn't have to do that if I could figure out how to get the multiplier to drop during idle.

Thanks.

If you use a multiplier higher than 22x to get to 3.7ghz then that might be the problem. For some reason anything higher than 22x during idle the multi will not drop. Try using 185 FSB...20x multi...that will put you at 3.7ghz. Now when you idle the voltage and the multi should drop. Make sure c-states and all power saving are turned on too.