ASUS P8P67 Pro & 2500K @4.9GHz 49x multi.. fluctuating vcore normal?

SaViOr-

[H]ard|Gawd
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Sep 10, 2004
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I posted this in a reply to my other thread, but figured that this is a better place for the post since its motherboard/bios related..

Currently, 1hr Prime95 stable at 4.9GHz 49x multi at 1.35v (HW Monitor Pro shows a min 1.34 max 1.38 vcore) Still working on figuring out why it fluctuates like that when I set it to 1.35 in bios... unless its supposed to? Also could cores 2/3 be hotter than 1/4 if thermal paste isn't on there evenly or enough? Or should I not worry about it... Sorry for all the questions :( my 955BE was always at 1.41 vcore and didnt fluctuate this much, maybe down to 1.40 . With the vcore at 1.32 I would BSOD at the start of Prime95, but with it set to 1.35 I'm good at the moment.

Temps -
Motherboard Currently at 26C

Min
27 28 27 26

Max
76 83 84 79

Again cores 2/3 jump up a little then drop back to that 77/78 range

May be able to get temps for cores 2/3 down if I can figure out how to keep vcore from moving so much. I guess my concern is, whether its normal for the vcore to fluctuate like that or is it supposed to stay constant under load? Right now CPU-Z shows 1.368 but jumps around a bit to 1.352, 1.360 or 1.376. Most of the time its 1.368 or drops to 1.360 but I've seen the other 3 values too while staring at it. Is this something that the motherboard does depending on what it thinks the cpu needs or?

Thanks, and again sorry for my noobiness.. Never really messed with This high of an OC or Intel OC in general
 
Last edited:

Adam1203

Limp Gawd
Joined
Feb 11, 2011
Messages
159
I posted this in a reply to my other thread, but figured that this is a better place for the post since its motherboard/bios related..

Currently, 1hr Prime95 stable at 4.9GHz 49x multi at 1.35v (HW Monitor Pro shows a min 1.34 max 1.38 vcore) Still working on figuring out why it fluctuates like that when I set it to 1.35 in bios... unless its supposed to? Also could cores 2/3 be hotter than 1/4 if thermal paste isn't on there evenly or enough? Or should I not worry about it... Sorry for all the questions :( my 955BE was always at 1.41 vcore and didnt fluctuate this much, maybe down to 1.40 . With the vcore at 1.32 I would BSOD at the start of Prime95, but with it set to 1.35 I'm good at the moment.

Temps -
Motherboard Currently at 26C

Min
27 28 27 26

Max
76 83 84 79

Again cores 2/3 jump up a little then drop back to that 77/78 range

May be able to get temps for cores 2/3 down if I can figure out how to keep vcore from moving so much. I guess my concern is, whether its normal for the vcore to fluctuate like that or is it supposed to stay constant under load? Right now CPU-Z shows 1.368 but jumps around a bit to 1.352, 1.360 or 1.376. Most of the time its 1.368 or drops to 1.360 but I've seen the other 3 values too while staring at it. Is this something that the motherboard does depending on what it thinks the cpu needs or?

Thanks, and again sorry for my noobiness.. Never really messed with This high of an OC or Intel OC in general

Are you using an offset or manual vcore?

The voltage will always be a little bit off due to vdroop, it's nothing to worry about.

I must say, 1.36 volts for a 4.9Ghz OC seems VERY low. The recommended vcore for that range is in the 1.4V ballpark. Are you prime95 stable with that voltage (running for 2+ hours)?

The motherboard will increase/decrease the applied voltage to the CPU based on usage (especially with an offset voltage setting).

You don't sound "noobish". :)
 

SaViOr-

[H]ard|Gawd
Joined
Sep 10, 2004
Messages
1,478
I'm in manual mode, and set it to 1.35v. I set the VRM Freq to 360, CPU Current Capability on 120% &LLC on Extreme. If anymore of the BIOS settings help, I can provide those.
Below is a pic of a 3 hour Prime95 run, you can see the vcore range in HWM Pro and also in CPU-Z. I ran all those windows during testing to ensure I can monitor everything thats going on :D.

4.9GHz 3hr Prime95 run

 

Falkentyne

[H]ard|Gawd
Joined
Jul 19, 2000
Messages
1,843
Nice overclock.
And yes, it's vdroop that is adjusting the voltage at load, but LLC is reducing the effect of this. You can't make it flawless (zero vdroop whatsoever) without using a Maximus IV extreme.

BTW, on your CPU, what is the default VID @ 3.4 ghz? You can use Realtemp to check by clicking "disable turbo", and the vid button at top right, as long as you aren't using any C states (system must run at 3.4 ghz instead of 1.6 ghz). BIOS will also show, as "target" voltage (not under health monitoring, though).
 

SaViOr-

[H]ard|Gawd
Joined
Sep 10, 2004
Messages
1,478
Nice overclock.
And yes, it's vdroop that is adjusting the voltage at load, but LLC is reducing the effect of this. You can't make it flawless (zero vdroop whatsoever) without using a Maximus IV extreme.

BTW, on your CPU, what is the default VID @ 3.4 ghz? You can use Realtemp to check by clicking "disable turbo", and the vid button at top right, as long as you aren't using any C states (system must run at 3.4 ghz instead of 1.6 ghz). BIOS will also show, as "target" voltage (not under health monitoring, though).

When I check disable Turbo it stays at 1600mhz? Or do i need to disable all the C states in bios first?

Also for voltage, do i go by what HW Monitor Pro is telling me or do I go by the VID in Real Temp, which btw what exactly is VID? It seems to always be around .05 higher in Real Temp than in HWM Pro.
Right now im at 5.0GHz, 1.38v set in bios with LLC on Extreme. Real Temp shows 1.42-1.44VID during AIDA64 Stability Test. HWM Pro shows min 1.37, max 1.4vcore
 

Falkentyne

[H]ard|Gawd
Joined
Jul 19, 2000
Messages
1,843
When I check disable Turbo it stays at 1600mhz? Or do i need to disable all the C states in bios first?

Also for voltage, do i go by what HW Monitor Pro is telling me or do I go by the VID in Real Temp, which btw what exactly is VID? It seems to always be around .05 higher in Real Temp than in HWM Pro.
Right now im at 5.0GHz, 1.38v set in bios with LLC on Extreme. Real Temp shows 1.42-1.44VID during AIDA64 Stability Test. HWM Pro shows min 1.37, max 1.4vcore

You need to disable all c states and eist first.
Disable turbo should put the CPU back at 3.4 ghz.

And don't test VID in realtemp at load. VID goes higher at load. it's only accurate at idle.
The VID shown in realtemp should match the "Target" VID shown in the BIOS.
 
Last edited:

Forceman

[H]F Junkie
Joined
Aug 7, 2005
Messages
9,243
The core temp difference thing is normal - they often have up to a 10C spread with these chips.
 
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