Friend's PC (CPU) Overheating After Thermal Paste Replacement

Rain08 · 26 Apr 2017

So I was helping my friend a couple of days ago on "repairing" his PC. It's a 3 year old PC that he uses a couple of hours every day. He said that it won't boot anymore after cleaning it. So I sorted it out to only find out that the RAM is not seated properly. However I also convinced him to also change the thermal paste in his CPU as part of his cleaning. I hadn't thought of taking CPU temps before the paste replacement because temps weren't my concern (nor he is) at the time. However when I installed HWMonitor I was shocked when I noticed the idle temps. It's hovering around 50~65 °C. When we tried to play Arma 3 (Zeus, testing the effects of high AI units), the CPU temps got around 70~85 °C and sometimes spiking to 90. The ambient air temp was around 32~34 °C but still it shouldn't reach that high (well I think it shouldn't). I know there's something wrong with but it seems I can't find it. The ventilation is very good (cables aren't obstructing the fans), we even had the side panel removed to see if it can improve some things.

I decided to test things further by using Nvidia Flow (kinda like Flex but for smoke effects). I know that the software is not CPU bound but I needed something fast and easy to use at the time. I was actually shocked that the CPU is reaching around 70~80 °C with this software (what more if I used something that can properly stress the CPU). Compared to my CPU when I had the Flow running, it doesn't even reach past beyond 58 °C.

I don't know if this is his real everyday temperatures because he doesn't monitor it. So I don't really know if this problem existed a long time ago or just when we had the thermal paste reapplied.

tl;dr CPU is hitting high temperatures after thermal paste replacement. Even at idle, the CPU is getting around 50~65 °C.

His specs:
W10
i7-4790 (stock cooler)
Asus H97M-E
8 GB (2x4) 1600 MHz HyperX
Asus Strix GTX 750 Ti
FSP Raider 550W

My specs:
W7
Pentium G3258 @3.8 GHz/1.092V (stock cooler)
Gigabyte Z97-HD3
8 GB 1600 MHz Ripjaws
Palit SuperJetstream GTX 1060
Seasonic G550 550W

Album of the situation:
Overheating CPU - Album on Imgur

Also in that thermal paste pic, I decided to have it reapplied (2nd time) but it's still the same situation.

He's not able to spend much on a cooler. So I'm planning to get him the Deepcool GAMMAXX 200 CPU cooler to replace his stock one. I've seen reviews of this and according to them, it's pretty good.

Cliff S · 27 Apr 2017

I can't help much here, but one question comes to mind:
Did you, maybe, apply the thermal paste too thick?

With thermal paste, too thin is better than too thick, as too thick insulates then.

Berton · 27 Apr 2017

It's also best to put a dollop of the paste only in the center of the CPU, let the compression of fastening the fan spread it out which avoids air bubbles which in turn can cause poor cooling.

clam1952 · 27 Apr 2017

That is probably about normal for a stock cooler, using one on my 3770k machine and it's idling around 70C, doesn't go much above 85C under load though, keep meaning to replace it as it was only a temporary fix for the cooler I broke, snapped the metal clip when refitting after redoing the thermal paste.....
Edit: was around the 35 to 40C idle temp with a proper cooler.

Rain08 · 27 Apr 2017

Cliff S said:

I can't help much here, but one question comes to mind:
Did you, maybe, apply the thermal paste too thick?

With thermal paste, too thin is better than too thick, as too thick insulates then.

Berton said:

It's also best to put a dollop of the paste only in the center of the CPU, let the compression of fastening the fan spread it out which avoids air bubbles which in turn can cause poor cooling.

I only did a pea sized one for both replacements. I didn't spread it manually, I just let the HS/F do it.

Although I remembered LTT and Puget Systems did a test on various thermal paste application methods and concluded that as long as there's "enough" then the temperature difference won't be drastic. However I just did a pea sized one.

Looks like we're pushing a buy on that cooler that I mentioned (it's the "best" one that we can find given the availability and price). I can only update this situation next week. He's not doing any gaming on it after I saw those temps, only browsing and some desktop work.

Cliff S · 27 Apr 2017

Until he gets a new fan, just make sure he uses Balanced power option, and if he has a "K" SKU(unlocked) he shouldn't be overclocking it. Also if he has any of the other SKU's (R, S, or T): 4th Generation Intel Coreâ„¢ i7 Processors Product Specifications
and he's using Creators Update, he can limit the Maximum Processor Frequency(to help keep it cooler)Start reading here, to the end: Create Custom Power Plan in Windows 10 - Windows 10 Performance Maintenance Tutorials

solarstarshines · 27 Apr 2017

Stock coolers are crap even with mild Intel Cpu's they get high temps

I would look into better Case fans and a new CPU cooler doesn't have to be Liquid it just have to be better than intel's stock cooler

Just my two cents and it being the Philippines my wife's home Country i know the weather Humid Island weather doesn't help either

Rain08 · 27 Apr 2017

Cliff S said:

Until he gets a new fan, just make sure he uses Balanced power option, and if he has a "K" SKU(unlocked) he shouldn't be overclocking it. Also if he has any of the other SKU's (R, S, or T): 4th Generation Intel Coreâ„¢ i7 Processors Product Specifications
and he's using Creators Update, he can limit the Maximum Processor Frequency(to help keep it cooler)Start reading here, to the end: Create Custom Power Plan in Windows 10 - Windows 10 Performance Maintenance Tutorials

He's using a locked 4790 so there's no overclocking in that.

I actually forgot about being able to change the CPU's max operating frequency in the power plans(I use this sometimes to control the battery life in my laptop), I hadn't thought of it before. Anyway I told him to change it to 95% which brings his max clocks to 3.4 Ghz, when he played Arma 3 it's now averaging at around 60~70 °C and idle temps are around 35~45 °C. I might tell him to lower the percentage more later during the day because it might get hotter.

solarstarshines said:

Stock coolers are crap even with mild Intel Cpu's they get high temps
I would look into better Case fans and a new CPU cooler doesn't have to be Liquid it just have to be better than intel's stock cooler
Just my two cents and it being the Philippines my wife's home Country i know the weather Humid Island weather doesn't help either

He's still deciding on what CPU cooler he would get. Either the Deepcool GAMMAXX 400 or the Cooler Master Blizzard T2 Mini (the CPU cooler that I first mentioned isn't actually available).

Yeah, the weather isn't that great right now. Currently summer season, heat index averaging around 37~41 °C and only raining in the night like twice or thrice this month.