Core voltage fluctuations

[HazzyP]

Hi there,

Ive just ran cpuz on a evga 790i ultra board with an e8500 using a 620 corsair modular psu.

All standard setting, no overclocking.

The core voltage is showing up as 1.76 (on auto at 1.2) but it keeps dipping 0.1 or so causing the multiplier to drop to 6 from 9 and the processor speed to read as 2000mhz.

Is this a psu voltage problem or the processor? The processor has had a hard introduction running up to 100 degrees c on 4 or 5 occasions before I realised the previous settings were for a different processor (bought from a friend)

cheers.

 

[Daza]

A speed step is more than likely enabled so the multiplier will go to x6 when idle and x9 when under load (to save leccy = money)

Secondly NEVER and I mean NEVER use cpu-z to monitor voltage at the very least use lavalys everest or the supplied motherboard software monitoring tools.

And never take any psu voltage as accurate the only way is with a dedicated voltage monitor as no motherboard will report the accurate voltage for a psu.

 

[SwaleSmith]

sounds like speedstep check cpu config options in bios

 

[HazzyP]

Sorted, it was c1 or something, speedstep was off. Cheers mate.

By the way how do I know if my cpu has enough cvolts? Im running it at 3.3ghz using 1.1v. I cant underpower it can I?

 

[monkey7]

You'll notice when it does not have enough volts. Believe me, you will :'D

No really, if it does not have enough voltage it will simply fail to boot. Your motherboard will probably return your settings to stock in order to boot.

To detect it a little earlier make sure you run 2h+ Prime95 runs. If the cpu does not have enough voltage for the speed it runs at P95 will be getting errors, meaning you have to up the voltage.

 

[SwaleSmith]

wouldn't off thought it would undervolt your CPU would be the first I've ever heard of it.

You can try runnign prime95 thought to be sure....and whilst you there you can increase the fsb and vcore a touch, to make runnign prime worthwhile

 

[HazzyP]

No errors or anything, just a warm cpu and an oddly fluctuating 5v line, 0.7 to 6.2v?!

 

[Daza]

And never take any psu voltage as accurate the only way is with a dedicated voltage monitor as no motherboard will report the accurate voltage for a psu.

:wavey:

 

[monkey7]

Hmmm that's either a VERY bad psu and some VERY tough components or an incorrect reading.

Could you try lavalyst everest? (don't know if the free version actually displays all voltages, but it's worth the try).

 

[HazzyP]

its a brand new corsair hx620w, the 5v line is to a few fans I think.

 

[SwaleSmith]

HazzyP, don't worry about that its inacurate as mentioned above for acurate testing only a multimeter will work, you have a good PSU take no notice, the programs you must take witha pinch of salt to be honest.....you can check your 5v line by going into the bios and going into hardware monitor that would be more accurate

 

[HazzyP]

yeah bios is happy wit it. Nice one!

 

[SwaleSmith]