[SOLVED] Is CPU core difference of 20°C an issue and if so how would be I about fixing it?

gime114

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Mar 30, 2017
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I decided to do deeper investigation into why my laptop has such a serious issue when playing CPU intensive games (often dropping bellow 1GHz on the clock), I have changed the thermal paste and cleaned it out before, but I didn't notice a performance impact. Now while running a stress test I decided to check the CPU temp and how it behaves and I noticed that there is a masisve discreprancy in the core temps between the cores, so basically one core spikes up to the thermal limit and starts throttling the whole pc.

Now this wouldn't be a big deal, I did some reading and a difference of 10 is quite common and still withing within spec for a cpu. However I am seeing a difference of double of that. View: https://imgur.com/a/JLzWsJT


I have made sure to check that all cores were being hit by the stress test. Laptop Specs: https://www.asus.com/Laptops/ROG-GL553VD/specifications/
with the i5 / 1050 (4GB) configuration.
 
Solution
Temperatures between the hottest and coolest core within 10C is considered within spec, according to Intel.
There is a 21C difference between your hottest and coolest - that's not normal.
You've either not mounted the cooler correctly, or the die isn't making proper contact with the IHS.
It shouldn't be an issue, but it is quite peculiar.
this could mean that the contact between the cooler and the cpu is tilted onto 1 way, but it could also be that you have a cpu with 4 very different cores, since not cores are created equally.

If you play a cpu heavy game, but its heavy on just 1 core, like a minecraft server, while 1 core might spike to 100%, the others sit idle trying not to heat up too much and take less power, hence below 1ghz.
 

Phaaze88

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Temperatures between the hottest and coolest core within 10C is considered within spec, according to Intel.
There is a 21C difference between your hottest and coolest - that's not normal.
You've either not mounted the cooler correctly, or the die isn't making proper contact with the IHS.
 
Solution
I decided to do deeper investigation into why my laptop has such a serious issue when playing CPU intensive games (often dropping bellow 1GHz on the clock), I have changed the thermal paste and cleaned it out before, but I didn't notice a performance impact. Now while running a stress test I decided to check the CPU temp and how it behaves and I noticed that there is a masisve discreprancy in the core temps between the cores, so basically one core spikes up to the thermal limit and starts throttling the whole pc.

Now this wouldn't be a big deal, I did some reading and a difference of 10 is quite common and still withing within spec for a cpu. However I am seeing a difference of double of that. View: https://imgur.com/a/JLzWsJT


I have made sure to check that all cores were being hit by the stress test. Laptop Specs: https://www.asus.com/Laptops/ROG-GL553VD/specifications/
with the i5 / 1050 (4GB) configuration.

What app were you using to stress test? It might be the game engine which can "pin" a cpu core and run on it as a main thread.

However if this is something like AIDA64 or Prime95, I would say that core has a problem. I would ship it back if it's under warranty. If it's not, you are screwed. If repasting didn't solve the issue, you certainly aren't going to replace the CPU.

Cores are monolithic on this series so heat tends to distribute evenly. So it's something internal to the pathways that makes it run hotter.

There is a small chance of a badly applied TIM to the heat spreader. But again, this isn't something that can be fixed by a home user. Your heatsink might also be warped leading to bad contact area. The way to check is to put a drop in the middle and squeeze down and see how the paste spreads out. If it doesn't spready evenly the heat sink or CPU lid is likely warped.

But if one internal core runs at a constant higher frequency (CPU Pinned core) or has bad pathways (more voltage to stabilize) then it will run hot. They can dynamically adjust based on speed or internal settings on a per core basis. This is to promote stability.
 

gime114

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Mar 30, 2017
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What app were you using to stress test? It might be the game engine which can "pin" a cpu core and run on it as a main thread.

However if this is something like AIDA64 or Prime95, I would say that core has a problem. I would ship it back if it's under warranty. If it's not, you are screwed. If repasting didn't solve the issue, you certainly aren't going to replace the CPU.

Cores are monolithic on this series so heat tends to distribute evenly. So it's something internal to the pathways that makes it run hotter.

There is a small chance of a badly applied TIM to the heat spreader. But again, this isn't something that can be fixed by a home user. Your heatsink might also be warped leading to bad contact area. The way to check is to put a drop in the middle and squeeze down and see how the paste spreads out. If it doesn't spready evenly the heat sink or CPU lid is likely warped.

But if one internal core runs at a constant higher frequency (CPU Pinned core) or has bad pathways (more voltage to stabilize) then it will run hot. They can dynamically adjust based on speed or internal settings on a per core basis. This is to promote stability.

I used the integrated XTU stress test and the main reason I swapped thermal paste is because the warranty ended, so I felt better tinkering with my laptop. Are you sure it can't be a bad application of thermal paste? The laptop heat plates/pipes might not do a good job of spreading the thermal paste since they don't press down evenly while being screwed on.
 

gime114

Reputable
Mar 30, 2017
13
0
4,520
Temperatures between the hottest and coolest core within 10C is considered within spec, according to Intel.
There is a 21C difference between your hottest and coolest - that's not normal.
You've either not mounted the cooler correctly, or the die isn't making proper contact with the IHS.

I'll have to try and check how the paste looks under the heat spreader when I have the time.