[SOLVED] 10700KF High temps with Prime95 at 4 cores

u700

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Feb 21, 2019
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I have 10700KF with Noctua NH-U12S.

I put my Graphics card under 100% load and then run Prime95 small ffts to see if the CPU can cope with the combined heat.

When I run Prime95 with all cores, it runs at 4.05 Ghz and 80 degrees.
But when I run it with only 4 cores it runs at 4.66 Ghz and 97-100 degrees

PL1 is set to 125W and PL2 is 190W (5 seconds)

I feel a bit unfomfortable that the CPU is allowed to run indefinitely at 100 degrees. Is there a way to enforce a thermal limit when the CPU reaches, say 90 degrees?

Thanks
 
Solution
Prime95 small-FFT is about the worst-case scenario in terms of heat generation. Running it on 4 cores is going to allow greater turbo frequency and power on those cores as compared to all cores, while that same 125W/190W would be concentrated on about 1/2 of the die area, which in these days is just a couple tens of mm^2 per core.

Your CPU already has a temperature limit, though I'd be interested to know as well if there's actually a way to lower that.

If nothing else, you can reduce your PL1 and PL2 settings for little loss of performance in most applications.

JWNoctis

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Jun 9, 2021
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Prime95 small-FFT is about the worst-case scenario in terms of heat generation. Running it on 4 cores is going to allow greater turbo frequency and power on those cores as compared to all cores, while that same 125W/190W would be concentrated on about 1/2 of the die area, which in these days is just a couple tens of mm^2 per core.

Your CPU already has a temperature limit, though I'd be interested to know as well if there's actually a way to lower that.

If nothing else, you can reduce your PL1 and PL2 settings for little loss of performance in most applications.
 
Solution

u700

Commendable
Feb 21, 2019
21
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1,515
Current cooler too small for that...

Throw it all over games, sure.





Somewhere in the bios' advanced settings. Refer to the manual, or online manual.



I have Gigabyte B560M Aorus Pro. I've gone through the manual but there is no mention of that. From online search I've learned that Gigabyte motherboards are supposed to have an option "TJ MAX", which allows to thermal throttle at specified temperature. Based on screenshots found online I went exactly where this option is supposed to be and it's not there.



I sent an question to gigabyte support, they say they will respond within a week.



As an alternative solution, I found this option in the BIOS :

Active turbo ratios:

Turbo Ratio (1-core active) : 51
Turbo Ratio (2-core active) : 51
Turbo Ratio (3-core active) : 49
Turbo Ratio (4-core active) : 48
..and so on



I assume these let the user define what the boost shoot be at what number of active cores. I tried lowering these numbers but they don't work as epxected. I set 1-core and 2-core to 47, 3-core to 46, 4-core to 45. But it's not respecting my settings. It runs at only 4.5 Ghz even when just 1 core active. Or it runs everything at 4.66Ghz, even with 4 cores active and overheats.

Am I missing something or is this feature broken?

Also, for some reason in Intel XTU the multipliers are greyed out even though this is a K chip.
 

Phaaze88

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Active turbo ratios:

Turbo Ratio (1-core active) : 51
Turbo Ratio (2-core active) : 51
Turbo Ratio (3-core active) : 49
Turbo Ratio (4-core active) : 48
..and so on



I assume these let the user define what the boost shoot be at what number of active cores. I tried lowering these numbers but they don't work as epxected. I set 1-core and 2-core to 47, 3-core to 46, 4-core to 45. But it's not respecting my settings. It runs at only 4.5 Ghz even when just 1 core active.
That is by design.
When one core is active, it'll boost to 5.1. 2 cores active, also 5.1ghz. You won't really see these very often at all...
The 1 and 2 core ratios aren't really practical, due to the OS and any activities you're doing easily utilizing more than that.
Around the 4 core ratio is closer to the cpu's 'true turbo boost'.

I have Gigabyte B560M Aorus Pro. I've gone through the manual but there is no mention of that. From online search I've learned that Gigabyte motherboards are supposed to have an option "TJ MAX", which allows to thermal throttle at specified temperature. Based on screenshots found online I went exactly where this option is supposed to be and it's not there.
It's supposed to be in Advanced Mode > Tweaker tab > Advanced Cpu Settings.
You may need to update the bios.

Also, for some reason in Intel XTU the multipliers are greyed out even though this is a K chip.
If I remember correctly, adjusting multipliers is supposed to be locked on B chipset boards - memory is unlocked though.
At least, you can't raise the multipliers higher than their default ratios - that'd be overclocking them, which is exclusive to Z series.
 

u700

Commendable
Feb 21, 2019
21
3
1,515
That is by design.
When one core is active, it'll boost to 5.1. 2 cores active, also 5.1ghz. You won't really see these very often at all...
The 1 and 2 core ratios aren't really practical, due to the OS and any activities you're doing easily utilizing more than that.
Around the 4 core ratio is closer to the cpu's 'true turbo boost'.


It's supposed to be in Advanced Mode > Tweaker tab > Advanced Cpu Settings.
You may need to update the bios.


If I remember correctly, adjusting multipliers is supposed to be locked on B chipset boards - memory is unlocked though.
At least, you can't raise the multipliers higher than their default ratios - that'd be overclocking them, which is exclusive to Z series.

Thanks for the help. What I decided to try, is to cut the power limit PL1 to 95W. This way even at 4-core Prime95 small fft and and GPU at full load the temps don't exceed 84C as power limit kicks in. After doing this I notice no impact on performance in games, still boosts same as before. In case there is no way to adjust the tj max, this looks like a good enough solution.
 
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Is there a way to enforce a thermal limit when the CPU reaches, say 90 degrees?
ThrottleStop has a feature in its Options window so you can lower the thermal throttling temperature to whatever you like. Intel calls this setting, PROCHOT Offset. (processor hot)

WDjzBNv.png


The default thermal throttling temperature is 100°C. If you set PROCHOT Offset to 10, this will lower the temperature when thermal throttling begins to 90°C.

mM9EeMn.png


Some motherboards have a similar setting in the BIOS. My Asus Z490 board lets you enter the maximum CPU core temperature directly into the BIOS in the Ai Tweaker section.

VmCXGgi.png


Intel has been using the same 100°C maximum temperature for the vast majority of Core i CPUs produced since 2008. Some of their CPUs have been factory set to 105°C. I know these kind of temperatures make many users feel a little uncomfortable. Intel is in business to make money. If there were lots of warranty returns due to heat exhaustion, Intel would have lowered the thermal throttling temperature years ago.
 
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JWNoctis

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Intel has been using the same 100°C maximum temperature for the vast majority of Core i CPUs produced since 2008. Some of their CPUs have been factory set to 105°C. I know these kind of temperatures make many users feel a little uncomfortable. Intel is in business to make money. If there were lots of warranty returns due to heat exhaustion, Intel would have lowered the thermal throttling temperature years ago.

Right. I could remember my old Core 2 thermal tripping at 105°C, due to poor laptop cooling.

Maybe that's just because few home users would run their system at 90°C+ constantly for long, and that any massive cooling insufficiency or failure would tend to be rapidly evident with massive throttling or outright thermal shutdown, even though they couldn't be expected to last more than a few months at that temperature - Their VRM would have failed by then, even if the chips themselves won't for a while longer.
 

u700

Commendable
Feb 21, 2019
21
3
1,515
ThrottleStop has a feature in its Options window so you can lower the thermal throttling temperature to whatever you like. Intel calls this setting, PROCHOT Offset. (processor hot)

WDjzBNv.png


The default thermal throttling temperature is 100°C. If you set PROCHOT Offset to 10, this will lower the temperature when thermal throttling begins to 90°C.

mM9EeMn.png


Some motherboards have a similar setting in the BIOS. My Asus Z490 board lets you enter the maximum CPU core temperature directly into the BIOS in the Ai Tweaker section.

VmCXGgi.png


Intel has been using the same 100°C maximum temperature for the vast majority of Core i CPUs produced since 2008. Some of their CPUs have been factory set to 105°C. I know these kind of temperatures make many users feel a little uncomfortable. Intel is in business to make money. If there were lots of warranty returns due to heat exhaustion, Intel would have lowered the thermal throttling temperature years ago.

Thanks, this will be useful.

Also, if anyone's curious, I got a reply from Gigabyte, apparently Intel doesn't offer this setting in bios on their B560 boards, only Z590.