Laptop CPU Core to Core temp spread issues and high temps

[Mnky313]

basically my laptop's CPU temps had a ~20 degree spread with the liquid metal that it came with (it was applied by the previous owner, but the laptop did actually have an option for it from factory). So I assumed maybe he didn't do the best job applying it or it spread and wasn't properly covering all of the die, I opened it up and noticed that it looked like some of the die wasn't completely covered so I wiped off the liquid metal and applied normal paste (NT-H1, I don't have any liquid metal on hand), that did 'improve' the core to core deltas, now it's only about 10 degree but it's also 85-95 vs 75-95 so it really didn't make a difference.

what's weird is in Dave Lee's review of this exact laptop (expect it's an 8750h instead of a 9750h) the temps are amazing (like combined GPU and CPU maxes out at below 70c) where as my CPU reaches 95c without the GPU being loaded, would it be worth a try to buy some liquid metal and try and do a better job applying it or what? I'm kind of lost.
This is a run I just did:

(yes I see the weird dip in FPS on GT1, blaming Shadowplay. Didn't bother to re-run the test because score/GT1/GT2 don't really matter for what I am trying to talk about)

Screenshot from Dave Lee's review:

(He ran the Demo, I didn't) but even during the physics test his CPU and GPU was around 60-65c with basically the same clock speeds on the CPUs, I just don't know what to do to try and fix this. I hope I can get the CPU to actually reach max turbo under load instead of maxing out at like 3.6GHz under a load like Cinebench, any ideas?

[Light-Yagami]

The only thing I can conclude is that the previous owner messed with the cooling system and didn't put it back together properly.

 

And if it came equipped with LM from the factory (I've watched that video btw), then it shouldn't be repasted with a normal thermal paste, there's usually at least 15C difference. Temp spread suggests there isn't a uniform contact between the CPU die and the heatsink. Maybe previous owner switched the screws around, maybe he had to pull on the heatsink to get it apart for the first time and he ruined the tension of mounting brackets..

 

From what I see it's: Inferior TIM (thermal interface material - aka thermal paste) and bad CPU die contact.

[Mnky313]

2 minutes ago, Light-Yagami said:

The only thing I can conclude is that the previous owner messed with the cooling system and didn't put it back together properly.

 

And if it came equipped with LM from the factory (I've watched that video btw), then it shouldn't be repasted with a normal thermal paste, there's usually at least 15C difference. Temp spread suggests there isn't a uniform contact between the CPU die and the heatsink. Maybe previous owner switched the screws around, maybe he had to pull on the heatsink to get it apart for the first time and he ruined the tension of mounting brackets..

 

From what I see it's: Inferior TIM (thermal interface material - aka thermal paste) and bad CPU die contact.

Ok, I'll order some liquid metal and see if that makes a difference.
I'll also make sure to check the heatsink to see if it's slightly bent or the screws are different etc.

[Light-Yagami]

ALSO: There's this thing called "LM soak", where liquid metal reacts with copper alloy of the heatsink and absorbs into it partially, drying up in the process. That's why LM performance falls off after a while, needing additional LM to restore good die contact. That's probably part of the reason the laptop was running hot. Probably - if the previous owner did a poor job, there are many other things that could go wrong instead.

 

I hope this helps.

 

P.S: copper and gallium alloy that forms does not hinder performance. If you scrape it off the heatsink, you achieved absolutely nothing - but next time you apply LM, it'll just repeat the reaction and you'll end up with the same result. The best LM that I would recommend is that of Thermal Grizzly 

[Mnky313]

3 minutes ago, Light-Yagami said:

ALSO: There's this thing called "LM soak", where liquid metal reacts with copper alloy of the heatsink and absorbs into it partially, drying up in the process. That's why LM performance falls off after a while, needing additional LM to restore good die contact. That's probably part of the reason the laptop was running hot. Probably - if the previous owner did a poor job, there are many other things that could go wrong instead.

 

I hope this helps.

 

P.S: copper and gallium alloy that forms does not hinder performance. If you scrape it off the heatsink, you achieved absolutely nothing - but next time you apply LM, it'll just repeat the reaction and you'll end up with the same result. The best LM that I would recommend is that of Thermal Grizzly 

That's what I ordered, when I replaced the liquid metal (with paste) there was discolouration of the heatsink but I didn't scrape it off or anything. I just wiped it with alcohol for a bit until it wasn't easily coming off anymore, is there a better way to do this?
Thanks

[Light-Yagami]

1 minute ago, Mnky313 said:

That's what I ordered, when I replaced the liquid metal (with paste) there was discolouration of the heatsink but I didn't scrape it off or anything. I just wiped it with alcohol for a bit until it wasn't easily coming off anymore, is there a better way to do this?
Thanks

No, that is exactly what you're supposed to do. That discolouration is copper/gallium alloy I was talking about. It's a very thin layer, but it actually protects the copper beneath it - so It was good to leave it on. As its made of metal, it's high thermal conductivity doesn't hinder performance in any way and is purely cosmetic. Make sure that the heatsink is making proper contact with the die. Maybe don't open it until you get the LM delivered, and do it all in one go. These laptop components get tired pretty quickly, you don't know how many times it's been taken apart by the previous owner. Just a suggestion though, you're free to do as you will

 

If you see that heatsink isn't making proper contact with CPU die, see if you can bend the screw brackets in the opposite direction, so that when you screw it back into place, it puts more force on the CPU. Worst case scenario - you have to buy a new cooling assembly. 

[Mnky313]

Just now, Light-Yagami said:

No, that is exactly what you're supposed to do. That discolouration is copper/gallium alloy I was talking about. It's a very thin layer, but it actually protects the copper beneath it - so It was good to leave it on. As its made of metal, it's high thermal conductivity doesn't hinder performance in any way and is purely cosmetic. Make sure that the heatsink is making proper contact with the die. Maybe don't open it until you get the LM delivered, and do it all in one go. These laptop components get tired pretty quickly, you don't know how many times it's been taken apart by the previous owner. Just a suggestion though, you're free to do as you will

 

If you see that heatsink isn't making proper contact with CPU die, see if you can bend the screw brackets in the opposite direction, so that when you screw it back into place, it puts more force on the CPU. Worst case scenario - you have to buy a new cooling assembly. 

That was my exact plan, Ill leave it for now until the LM arrives, thanks for the suggestions. I'll probably try slightly bending the screw brackets back as there are 2 little tension arm things right near the CPU that could be a little loose, I'll make sure to check.

[Light-Yagami]

1 minute ago, Mnky313 said:

That was my exact plan, Ill leave it for now until the LM arrives, thanks for the suggestions. I'll probably try slightly bending the screw brackets back as there are 2 little tension arm things right near the CPU that could be a little loose, I'll make sure to check.

See, great minds think alike  

[Mnky313]

On 7/7/2020 at 8:03 PM, Light-Yagami said:

See, great minds think alike  

Liquid metal arrived earlier, after applying it to the CPU (didn't bother to do it on the GPU, it doesn't really matter as it hits power limit way before thermal limit and I didn't have conformal coating for the exposed SMDs around the GPU die)
Initially there wasn't any difference, 70s with a single core in the high 90s causing throttling issues but after removing some of the excess liquid metal everything is fine, at stock all cores sit in the 70s and even with both power limits set to 100W! it still keeps it from throttling (though with the 100W power limits the cores are in the 80s-low 90s.

Edit: Heatsink didn't look bent or anything, I did flex the little metal arms around the CPU to put more tension on it though I don't know if this fixed it or new liquid metal fixed it, either way it's fine now.

Updated Benchmarks!

Cinebench also went up from ~2800 to ~3050 so that's a decent improvement.

[Light-Yagami]

@Mnky313 I'm proud of you man! Great job