OC & Still use c-states

[Andreas W]

Hi, been a while since I posted regarding overclocking and such but it have come to my knowledge or something like that I don't really need my computer to be running at it's full power all the time since most times it don't need to.

I have overclocked my i7 860 and everything is set to manual in bios I have tried activating the C-states but nothing changes when I leave it at idle, so I disabled the c-states and left it at that. But just stumbled across a post on a different forum stating that I need to use the x22 multiplier with a certain c-states active which allow the cpu to turn of cores when not needed for instance the guy mentions c3 & c6. So before I actually do something I thought I would ask for advice which I would use without screwing with my OC or damage anything

 

[kbrady1979]

If I understand you correctly, you want the CPU to throttle down to an "idle" speed when not in use, and back up to your OC speed when needed. Two things come to mind: An Offset CPU voltage, and Enhanced Speed Step Technology. An offset voltage will allow you to have a much lower CPU voltage at idle speeds and a different voltage as your CPU is taxed. The idea is to not have the same voltage going to your CPU for OC speeds when it is at a much lower frequency. Intel's Enhanced Speed Step Technology should be enabled to allow it to conserve power when not in use by idling at a much lower clock speed.

 

[Andreas W]

Yes you understood it right, I did activate Speed Step 1 time at the same time when I tried activate C-State but it changed nothing like I wrote in my previous post but I am not using offset voltage because I am not quite sure how it works and it haven't been explained much in the O.C guides I have read, so I guess that explains why nothing changed when I tried the last time, but if I change the voltage to offset what should I start with never used it before.

 

[logicearth]

Did you change the "Minimum processor state" in the Advance options of Power within Windows of course? I have mine set to "0%" this allows the CPU to downclock to its absolute minimum.

 

[Andreas W]

Did you change the "Minimum processor state" in the Advance options of Power within Windows of course? I have mine set to "0%" this allows the CPU to downclock to its absolute minimum.

I have read about that also but I cant seem to find that option and me using Swedish language don't really help me locate it, is it because I'm not using a laptop? I just googled it and looked at images it does not exist for me

 

[Andreas W]

I know I am double posting but hopefully no harm done.

Ok so I have done this changed my offset using + and 0.560 something leaving me with a max vcore of 1.136 I changed to balanced energy plan and that or because of offset unlocked the "minimum processor state" I have just left it at 5% as minimum.

In bios I activated Speedstep and the full phase option is left on auto.
I did activate C-State on auto but that left me with a BSOD 3b even before I got into bios

But how does this sound so far? it is downclocking now so it seem to be working I haven't done any extensive stress testing yet

 

[GeneO]

Should be fine with speedstep. I have all of my C-states disabled and speedstep (EIST) enabled.

However, if you got BSOD with C states enabled and haven't tested fully for stability, it may not stable, though enabling c-states in the first generation i7 are well known to cause instabilities. Run prime95 for several hours at least.

What is your overclock frequency?
Good luck.

 

[Andreas W]

Should be fine with speedstep. I have all of my C-states disabled and speedstep (EIST) enabled.

However, if you got BSOD with C states enabled and haven't tested fully for stability, it may not stable, though enabling c-states in the first generation i7 are well known to cause instabilities. Run prime95 for several hours at least.

What is your overclock frequency?
Good luck.

Right now it's at 181x21 (3.8 Ghz) with 1.16 vcore tested with superpi went through the whole list from 16k to 32m, tried IBT and it passed that. I turned HT off since it don't do anything for me to reduce voltage and heat, used this setting for a couple of days now and no BSOD anymore at startup or while I use it.

And one forum thread I read said something about if you have C-State on the computer it uses 1 core at bootup with 26x multiplier or something so if that is true that would be what would cause the BSOD considering 26x181 is quite high