I get a lower cpu voltage than what's set on Asus PK5-e. Ideas?

[ocfun]

Will the REAL CPU Voltage PLEASE Stand UP! :lol:

Using asus pk5-e wifi, I manually set the cpu voltage to 1.4125v, save/exit/reboot and go back to bios and check the monitor page to find it's 1.304v. That is .108 lower than what I set it. If I boot to windows and check asus probe it's also 1.30v. cpu-z reports 1.300. So, I'm not sure what the voltage is really set to. If I want to end up with 1.3 volts in the monitor, I have to add .108 and enter 1.408 to end up with that. Does this sound abnormal for the pk5-e or is this typical of most boards like this and I should expect it?

I'd never want 1.5v which is high, but if I did, I'd have to enter 1.608 which would make me wonder if it wasn't too much. Can anyone with a pk5-e tell me what theirs is like? Or maybe lots of boards do this and it's common place just like when temps are some times misreported in different software? Maybe I just need another bios update, but I have the latest non beta. hmm.

 

[dagger]

As far as I know, it happens on all boards. The vcore reporting in Windows will be lower than BIOS settings. The BIOS setting should be the accurate one.

 

[johnnyq1233]

Not true....
My board (see below) reports ram @1.98v in bios and on cpuz, fox one,etc.
CPU is @1.35v both bios and windoze.
What are your system specs....cpu,psu,video,etc

 

[jsc]

It's called "droop". My 680i board does the same thing. At default values, there's not much difference. But the more you push for a high OC, the greater the difference seems to be.

When I set the vcore to 1.500 volts in BIOS, everything reports about 1.42 volts.

Online, there are mods described to "fix" this "problem". Besides professionally, I have been tinkering with electronics about 50 years now. But this, I leave alone. I figure that the engineers who designed the motherboards are smarter than I am.

 

[roadrunner197069]

Common on P5K vanilla boards for sure.

 

[ocfun]

Thanks for responses. It's good to know it's common since I hoped it wasn't the board. I got the impression that you set it first, but then the voltage that BIOS reports in the monitor is the correct one. In other words, type the number in as 1.4125v. Save changes to BIOS and reset. Then go back into BIOS and visit the monitor screen. In there it will give out a cpu voltage of 1.304v. This will also match with programs in windows later. That one should be the true voltage. But I must admit, I'm not sure.

Then I read about someone else having a similar question as mine. Someone told them it had to do with a setting called "voltage damping" Or something like that. But I see no setting like that, unless I missed it?

As for "droop", I heard that was the result of switching from idle to an intense program like prime 95. The voltage droops down a tiny amount as soon as the program is launched. It happens on my other Asus board, but it never hurt anything. But having it report a lower voltage could easily be droop too, so now I've heard it described two ways. And not to disagree with you jsc. I'm just saying someone else on Toms thought was using it differently. So thanks to explaining it.

roadrunner, You say it's common on P5K vanilla boards. I have the p5k-e Wifi edition. Maybe that's vanilla compared to the deluxe? But the fact that you tell me that, makes me feel better about it. Thanks for replies.

 

[chookman]

Another explaination could be speedstep or C1E, they will decrease voltage in relation to cpu usage.

 

[dagger]

Vcore drop, or Vdroop, only happens when your processor is under full load. You can turn on LoadLine Calibration in BIOS, if your motherboard supports it.

Speedstep lowers multiplier, you'll notice it in cpuz right away.

 

[chookman]

Vcore drop, or Vdroop, only happens when your processor is under full load. You can turn on LoadLine Calibration in BIOS, if your motherboard supports it.

Speedstep lowers multiplier, you'll notice it in cpuz right away.

From Zorg on the C2D not running full speed stickie
Clearly explains that EIST and C1E can have an effect on vcore (which i believe C1E will still work in the BIOS)

BIOS Setting: EIST Enabled C1E Disabled
In XP you need to set Control Panel -> Power Management -> Minimal Power Requirements to enable EIST.
EIST only works with the stock frequency - no overclock.
It will adjust the multiplier and Vcore.
It will adjust only the multiplier if the Vcore is set to manual in the BIOS.
Right click My Computer and click Properties will give a current snapshot of the CPU frequency under the General Tab.

BIOS Setting: C1E Enabled EIST Disabled
No settings in XP are required.
It will work at stock frequency and overclock frequencies.
It will adjust the multiplier and Vcore at the stock frequency.
It will adjust only the multiplier if overclocked or the Vcore is set to manual in the BIOS.
Right click My Computer and click Properties will NOT give a current snapshot of the CPU frequency under the General Tab.

 

[ocfun]

That's true chookman. I noticed speed step changing my multiplier to 6x and it surprised me the first time I saw it. I kept wondering why it was running slower. lol. But I didn't know speedstep could lower voltage. I guess it makes sense since it's a power saving feature. Thanks for that and for posting the effects of IEST and C1E.

Also thank you for clarifying that it only happens under full load dagger. I will be working with it more today and will look for "LoadLine Calibration". Hopefully it's in my bios. My only new concern is that my VID is like 3.125 which is the highest for a G0 from what I heard. I hope it doesn't mean I got a more voltage hungry/hotter chip which will limit over clocks.