Question CPU overclock voltage ?

quadrax

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Hello there,

I am curious why my settings in BIOS are set to static, why it fluctuates to lower frequency while stress testing ?
For example, i have set up 50x multiplier, 1.4v and everything seems ok, until i start stress test ( OCCT ) and then not only frequency went down, but also voltage (vcore).
I disabled everything what can do this (power savings etc.) and still this happens.

Or vice versa - I tried undervolt, so i set 1.220v and 45x multiplier, but when i start stress test - vcore raises up to about 1.35v which is insanely much for that frequency. I am confused what happens and why it happens..

Temps are acceptable. ( iam not running power virus like linx )

Thanks for every advice.


My rig :

CPU : Intel Core i5-11600KF
CPU Cooler : Noctua NH-U12A
GPU : EVGA RTX 3070
MB : ASUS Prime-P Z590
RAM : 4x16 GB RAM Corsair Vengeance, 3200MHz
PSU : Seasonic GX 1000w
2 x NVMe SSD
2 x SATA HDD
 

keith12

Champion
Hello there,

I am curious why my settings in BIOS are set to static, why it fluctuates to lower frequency while stress testing ?
For example, i have set up 50x multiplier, 1.4v and everything seems ok, until i start stress test ( OCCT ) and then not only frequency went down, but also voltage (vcore).
I disabled everything what can do this (power savings etc.) and still this happens.

Or vice versa - I tried undervolt, so i set 1.220v and 45x multiplier, but when i start stress test - vcore raises up to about 1.35v which is insanely much for that frequency. I am confused what happens and why it happens..

Temps are acceptable. ( iam not running power virus like linx )

Thanks for every advice.


My rig :

CPU : Intel Core i5-11600KF
CPU Cooler : Noctua NH-U12A
GPU : EVGA RTX 3070
MB : ASUS Prime-P Z590
RAM : 4x16 GB RAM Corsair Vengeance, 3200MHz
PSU : Seasonic GX 1000w
2 x NVMe SSD
2 x SATA HDD
Hey there,

This is known as vdroop when the voltage drops. This happens when the mobo doesn't provide the voltage specified in the bios. This can be offset by changing LLC to a higher level. For LLC, typically there are 4 levels. Somtimes it's 1,2,3,4. Other mobo's it's low, medium, high etc.

But why are you pumping 1.4v static? This is not good for the CPU over the longterm.

For the increase in voltage when undervolting, there must be some setting that's effecting that. It shouldn't really go above if you've set it fixed.
 

quadrax

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Feb 5, 2018
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Hey there,

This is known as vdroop when the voltage drops. This happens when the mobo doesn't provide the voltage specified in the bios. This can be offset by changing LLC to a higher level. For LLC, typically there are 4 levels. Somtimes it's 1,2,3,4. Other mobo's it's low, medium, high etc.

But why are you pumping 1.4v static? This is not good for the CPU over the longterm.

For the increase in voltage when undervolting, there must be some setting that's effecting that. It shouldn't really go above if you've set it fixed.
Hello. Thanks for explaining. I would like to ask, can do LLC (highest) possible damage motherboard in long-term condition? CPU 1.4v i think its not problem, i need even more for being stable, because Cinebench R20 just freezes immediatly.
 

keith12

Champion
Hello. Thanks for explaining. I would like to ask, can do LLC (highest) possible damage motherboard in long-term condition? CPU 1.4v i think its not problem, i need even more for being stable, because Cinebench R20 just freezes immediatly.
I would drop the OC a bit, if you have to use 1.4 to achieve stability. LLC on it's highest level can overvolt your CPU. It's about finding a balance.
 

quadrax

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I would drop the OC a bit, if you have to use 1.4 to achieve stability. LLC on it's highest level can overvolt your CPU. It's about finding a balance.
True, but i am not sure, if i can cool it, doesnt matter if its 1.45v or 1.4v ? I know how works LLC, dont worry. Trying to find balance, but waitin for my AIO cooler, then i can experiment more. Probably should be safe 1.45v, isn't it?
 

keith12

Champion
True, but i am not sure, if i can cool it, doesnt matter if its 1.45v or 1.4v ? I know how works LLC, dont worry. Trying to find balance, but waitin for my AIO cooler, then i can experiment more. Probably should be safe 1.45v, isn't it?
For me, you are putting too much voltage through to achieve your OC. You need to dial it back.

Your temps at max load (Prime95) should be below 80c for 24/7 OC.
 

quadrax

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For me, you are putting too much voltage through to achieve your OC. You need to dial it back.

Your temps at max load (Prime95) should be below 80c for 24/7 OC.
What if i say - 1.35 - 1.39v (idle) and in load 1.45v (through highest LLC). Is this should be considered as safe? Temperatures are problem (at this moment), because i am still waiting for my AIO cooler delivery. Then i think i can manage temperatures.
 

Zerk2012

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What if i say - 1.35 - 1.39v (idle) and in load 1.45v (through highest LLC). Is this should be considered as safe? Temperatures are problem (at this moment), because i am still waiting for my AIO cooler delivery. Then i think i can manage temperatures.
I would not go over 1.38, why burn up your stuff? You got more that just the processor that needs to be able to handle the voltage.

In real world performance you would probably never tell the difference in 4.8 and 5.0.

From this only the top 17% can hit 5.0 on all cores.

Rocket LakeAll Core SSE FrequencyAll Core AVX2 & AVX512 FrequencyPer Core FrequencyAll Core Die Sense VcorePower Limit% Capable
11600K4.80GHz4.70GHz2C+100MHz1.340V200W100%
11600K4.90GHz4.80GHz2C+100MHz1.360V210WTop 81%
11600K5.00GHz4.90GHz2C+100MHz1.380V220WTop 17%
 
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quadrax

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I would not go over 1.38, why burn up your stuff? You got more that just the processor that needs to be able to handle the voltage.

In real world performance you would probably never tell the difference in 4.8 and 5.0.

From this only the top 17% can hit 5.0 on all cores.

Rocket LakeAll Core SSE FrequencyAll Core AVX2 & AVX512 FrequencyPer Core FrequencyAll Core Die Sense VcorePower Limit% Capable
11600K4.80GHz4.70GHz2C+100MHz1.340V200W100%
11600K4.90GHz4.80GHz2C+100MHz1.360V210WTop 81%
11600K5.00GHz4.90GHz2C+100MHz1.380V220WTop 17%
1) I dont want burn up any stuff, but trying to get max "juice" from it. And this procesor is capable of 5.0GHz on all cores, just with more volts. 1.45v is stable, tried it, but cant handle temperatures with AVX stress tests

2) In real world i barely see difference thats true, however i was always fan to hit 5GHz and also i can use it very well.

3) Well i dont know from what source it is, but this is silicon lottery. Mine isn't, but that doesn't mean i can't try it to achieve 5GHz on all cores, just with little more volts.
 

Zerk2012

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1) I dont want burn up any stuff, but trying to get max "juice" from it. And this procesor is capable of 5.0GHz on all cores, just with more volts. 1.45v is stable, tried it, but cant handle temperatures with AVX stress tests

2) In real world i barely see difference thats true, however i was always fan to hit 5GHz and also i can use it very well.

3) Well i dont know from what source it is, but this is silicon lottery. Mine isn't, but that doesn't mean i can't try it to achieve 5GHz on all cores, just with little more volts.
5.0 is not a magic number, I can run my 10600K faster than 4.8 but no reason to.

The silicone lottery numbers are from the processors they have tested but they sell the top performers for a extra cost.

Your processor and motherboard do as you wish. 1.45🧨

EDIT from my above post.
From this only the top 17% can hit 5.0 on all cores. ( @ a safe voltage)
 
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quadrax

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FYI : Actually i am at 5.0GHz and i am satisfied.

vCore -Adaptive offset (-), 0.280 additional , 0.30v ----------- 1.376 idle / 1.394v load
VCCIO CPU : 0.800v
VCCIO MEM : 0.950v
CPU SA : 0.950
LLC 7
 

Karadjgne

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LLC is an added voltage. To everything. When the cpu demands voltage, it's an instant and hard hit to the VRM's, which needs a little time to recover. If the cpu then demands voltage again, before the VRM's can recover fully, that's the purpose of the LLC, to make up the difference. However, LLC gets added to everything, both the vdroop and the peak.

For instance if you have vcore at 1.35v and the cpu hits, it demands that power now, not later. So power potential might drop to 1.2v. An added 0.15v LLC brings that back upto 1.35v waiting on the next cpu demand hit. If that hit is slower and the VRM's work their way back upto 1.35v in time, the LLC is still present, so the total voltage is 1.35v + 0.15v, or 1.5v total.

And that's bad news. LLC for almost All general OC requirements should not be over 60-66%, level 3 out of 5, level 4 with very high OC. Never level 5. That's realistically reserved for LN2 overclocks. If your bios has a 7 level LLC choice, should be level 4, possibly level 5 at most.

Extreme LLC is reserved for Extreme OC, and a 5.0GHz OC on an 11th gen cpu is Far from Extreme, it's barely over stock clocks. 5.3GHz would be closer to Extreme requirements.

You set a large negative offset (that applies to the VRM's, not the cpu directly) and then made up the difference with a large LLC? That's creating higher voltages than necessary, which is why your load voltages are actually higher than idle voltages.

There's 2 main voltages. Vcore and VID. Vcore is basically what's demanded by the cpu (not necessarily what's actually used). VID is how much the VRM's supply. The offset voltage gets applied to VID, not vcore, so if the cpu wants 1.2v and your offset has lowered VID to 1.1v, it's on LLC to make up the difference or fail and the cpu crashes. VID and offset should always add upto just a fraction more than vcore, without LLC necessity. LLC should only be necessary for VRM's recovery times, not as a supplement.

Big voltage swings create instability, which OCCT isn't good for discovering, being a semi-stable demand. Once you start gaming, you'll find you'll bsod far more frequently.
 
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quadrax

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Thanks for explaining. I think LLC 7 should be ok. I am certainly watching whole voltages during stress testing or gaming ( got 2 monitors ). I tried set lower LLC, but then i crashes almost everytime, because vdroop is really noticeable. On other hand, i am not over magically 1.4v and i consider it as safe voltage. Even 1.45v should be ok. Motherboard and VRM's are in good condition (great temperatures) even in stress testing. I think they can handle LLC 7 in long terms.

OCCT is not perfect i know. But i do also other things for maximum stress test. For example : Playing DOOM, rendering, and on background playing 2K video.
 

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