replaced paste and fan, now computer shuts off w/o warning

[smoked cheese]

Back in 2013 I bought a prebuilt "gaming" computer online. It would always freeze after a while when playing resource intensive games such as Planetside 2, Total War: Warhammer, Assassin's Creed Unity, TES: Online, etc. However, it did work with AC: Black Flag, Fallout 4, and ArmA 3.
Never thought about doing anything to fix the problem until recently. I didn't really ask anyone for help or know I had to do to remedy my problem, and im no real expert, so I sought for solutions aimlessly.

A couple months ago replaced my Radeon HD 6670 with a RX 480. Other than giving my games a better look, it didn't really solve my computer freezing issue.
After that, I installed an SSD drive and set up WinOS on there. Not really sure what it did but i think my computer boots up faster. Freeze issue still present.
Then, a couple nights ago, on advice from my neighbor(s), I replaced my CPU fan and thermal paste. The old paste was there ever since I got it in 2013 and it was pretty dry and the chip was stuck to the heatsink so I used 70% isopropyl alcohol to help pry it off and clean it with, and squeezed on some Arctic Silver
Now, instead of just freezing, the computer would just shut off when playing games, including those that didn't freeze the computer when I played them. Used to be that it would shut off even when idling, but i'm not aware of what I did to fix that :/

I did some benchmarking and saw that my CPU would go up to high 80s (~86-88*C) creeping to 90*C before shutting off.

Any help or tips would be appreciated, many thanks in advance.

 

[LowlySkeleton]

Woah, sounds like your CPU is overheating.

You might want to try removing that heatsink and thoroughly cleaning off all the thermal compound with 99% isoproply, or the 70% one that you already have one hand. Now, the most important part would be to apply the correct amount of thermal compound; too little will result in little surface area contract between the cpu and the heatsink for heat transfer, but too much will result in there being an insulating effect (the compound will actually act to retain more heat than it transfers). The rule of thumb is a "pea-size" amount, though MUCH smaller than an actually pea! Ideally, you would want to be able to remove your heatsink and see that there was only just enough thermal compound to cover the surface of your cpu. If the thermal compound is spilled over and surrounding the cpu, you know you have applied way too much.

The second most important part would be to mount your heatsink back on again. The mounting pressure is what helps spread out the thermal compound without creating any air bubbles. Getting rid of air gaps and providing proper contact between the surface of the cpu and heatsink is the sole purpose of the thermal compound. If you lift up your heatsink any point when mounting it, it is best to start over and clean off all the thermal compound again.

Once everything is properly reapplied, mounted, and secured, you should run something like prime95 and monitor your thermals again.

 

[James Mason]

CPU is still overheating, and sounds like it always was. So you need a different CPU cooler, not just new thermal paste.

 

[smoked cheese]

CPU is still overheating, and sounds like it always was. So you need a different CPU cooler, not just new thermal paste.

what do you mean by that? Am i supposed to be getting a new heatsink?

 

[LowlySkeleton]

Your pc might have been already having issues with overheating when it originally started freezing up, which is what James Mason is trying to say. This might have been either due to having a weak cpu cooler or poor case cooling overall.

Since it seems to have been worse AFTER you replaced the cpu cooler and thermal compound, I was suspecting that you might have either applied too much thermal compound or have not mounted the heatsink properly, introducing air gaps or air bubbles.

It should also be noted that adding in a beefier gpu will usually add more heat to the internal environment of your pc case. If you do not have adequate case cooling, no expensive cpu cooler will help, as the heat still needs to find a way out of the case properly.

 

[smoked cheese]

Your pc might have been already having issues with overheating when it originally started freezing up, which is what James Mason is trying to say. This might have been either due to having a weak cpu cooler or poor case cooling overall.

Since it seems to have been worse AFTER you replaced the cpu cooler and thermal compound, I was suspecting that you might have either applied too much thermal compound or have not mounted the heatsink properly, introducing air gaps or air bubbles.

It should also be noted that adding in a beefier gpu will usually add more heat to the internal environment of your pc case. If you do not have adequate case cooling, no expensive cpu cooler will help, as the heat still needs to find a way out of the case properly.

At the time of writing, I had just taken apart my heatsink and cpu and wiped it down with 91% isopropyl alcohol, and i'm about to replace with less paste .

My computer sits in a small room and the case has ventilation holes on the back, front, bottom, and top. The backside is more than a couple inches away from the wall, and the bottom side has almost but less than an inch between itself and a surface. The topside and frontside has plenty of space to exhaust air from.

My GPU itself has two fans that I can manually control or allow it to run by itself, and it usually hovers at 60*C when gaming.

My CPU fan I picked wasn't chosen for gaming or anything, but rather for less noise pollution.

What are my options from here on out? My dad and neighbor tell me I should take it to the shop but that's the last option I want to take if I could solve this issue myself.

 

[LowlySkeleton]

Rather than just ventilation holes, do you have any fans mounted to the case itself? Ventilation holes will only really provide passive cooling. You would want to have at least a fan or two to help it out.

Here is a video that might help decide how to improve your case cooling: https://www.youtube.com/watch?v=8OmkmluAYAQ

More fans for active cooling will lower the case temps, and perhaps help with our overheating situation.

 

[smoked cheese]

Rather than just ventilation holes, do you have any fans mounted to the case itself? Ventilation holes will only really provide passive cooling. You would want to have at least a fan or two to help it out.

Here is a video that might help decide how to improve your case cooling: https://www.youtube.com/watch?v=8OmkmluAYAQ

More fans for active cooling will lower the case temps, and perhaps help with our overheating situation.

I have a 70mm CPU fan and a 120mm fan in the back, as well as a fan in front (idk dimensions), so I think I'm good with that.

 

[LowlySkeleton]

Case fans should be good, but that is one tiny cpu cooler! You should consider getting a heatsink with a 120mm fan that fits in your case. Something like a CM 212EVO might be a decent option.

 

[smoked cheese]

Case fans should be good, but that is one tiny cpu cooler! You should consider getting a heatsink with a 120mm fan that fits in your case. Something like a CM 212EVO might be a decent option.

My case is a thermaltake commander that is ~7 inches or ~19cm across, an my computer runs on a gigabyte AMD 970. Would 212EVO compatible and be able to fit into my tower?

 

[smoked cheese]

UPDATE: I reapplied with less thermal paste, and plugged in my computer back together AND put on its covers (I left one of them open because I figured I would be working on it again and didn't really want to have to screw it back in just to take it off later). I launched ArmA 3 and used MSI Afterburner to monitor my CPU temp. This time, it stayed at a steady 69*C without climbing to 80*C and beyond like it did when i tested it before reapplying thermal paste and slapping on my covers. I'm not sure if what I did has any significance but I'm going to test it with some other games before I come out with a verdict.

 

[smoked cheese]

(FINAL?) UPDATE: I did some more tests, and determined that my problem has been solved. I'm not sure whether it was closing the case or applying less paste was what solved it, but hey, as long as it works ¯\_(ツ)_/¯.

Big thank you to all those who provided advice and aid