[SOLVED] Can a cpu cooler affect GPU temps?

[AlxR25]

So lately I've seen my GPU temps rise by a lot. I'm rocking the Intel core i5 10400f with a GTX 1660Ti. When i first got the setup i was using the stock intel cooler but my CPU temps where too high so i swapped it up with an Arctic freezer 34 esports duo. So i think that since then my GPU temps have been rising. I tried to change my gpu thermal paste after the temps where insane (around 87C under load and 50-55c idle) so then it dropped back to 78C under load and 47C idle. Then after like 2 months i swapped the entire case to improve airflow and the temps dropped dramatically (around 69C to 72C under load and 38C idle). The past 3 days I've been experiencing high temps again while playing apex legends. Yesterday it got up to 87C and I start to believe that the problem is again airflow. Since there's a bulky CPU air cooler right above the GPU (You can check my profile pic for more info.) I believe that my cpu cooler keeps the heat on it and it's transmitted to the GPU. Later that day i played from my friends pc and i noticed that his CPU and GPU temps are almost identical (around 66*C both). So i thought that if i probably get an AIO where heat moves to the radiator which will be on top of the case away from the GPU it'll maybe fix my problem. Any advice?

 

[tennis2]

The AF 34 ESD isn't to blame here. It's blowing air toward the rear case exhaust fan. It's not "blocking" anything. The GPU pulls its air from underneath, and blows "up" toward the CPU cooler.

Most modern GPUs will target 73-75C under load and adjust fan speed accordingly. GPUs from the past couple generations will turn off their fans below ~55C.

Can you include fan speeds (rpm) in your observations?

 

[AlxR25]

The AF 34 ESD isn't to blame here. It's blowing air toward the rear case exhaust fan. It's not "blocking" anything. The GPU pulls its air from underneath, and blows "up" toward the CPU cooler.

Most modern GPUs will target 73-75C under load and adjust fan speed accordingly. GPUs from the past couple generations will turn off their fans below ~55C.

Can you include fan speeds (rpm) in your observations?

idk abt my fan speeds with RPM i've never checked it but my custom fan curve is just low like under 50% speed below 58C and when it reaches 64C it's going on 65% and above 68*C it's pumped up to 100%. i think my max fan speed on the gigabyte gtx 1660ti is around 1800rpm or 2000rpm

 

[geofelt]

What might have changed since 3 days ago when all was well?
I do not see the make/model of your case nor the fan arrangement.
Two 120/140mm front intakes and one 120mm rear exhaust should be good.

Dumb question... are the cooler fans both oriented to send cooling air from the front of the case to the back?
38c. at idle suggests your cooler is mounted well and functioning.

 

[tennis2]

I suspect that when you had your stock Intel cooler installed and CPU temps were high, case fans spun faster (variable speed case fans are controlled off of CPU temp by default). When you got the new cooler and lowered CPU temps, the case fan speeds dropped respectively. This results in lower case airflow, which means the GPU waste heat isn't being cycled out as quickly, resulting in higher internal air temp, which the GPU is inhaling.

 

[AlxR25]

I suspect that when you had your stock Intel cooler installed and CPU temps were high, case fans spun faster (variable speed case fans are controlled off of CPU temp by default). When you got the new cooler and lowered CPU temps, the case fan speeds dropped respectively. This results in lower case airflow, which means the GPU waste heat isn't being cycled out as quickly, resulting in higher internal air temp, which the GPU is inhaling.

so you're telling me that I should find a program or log into my bios and higher the speed of my case fans?

 

[tennis2]

so you're telling me that I should find a program or log into my bios and higher the speed of my case fans?

I prefer to use BIOS in lieu of having >>> background software running.
Software is nice for "on the fly" adjustments if you're testing settings and need to frequently make changes. I prefer to use BIOS settings once you've got everything finalized and are ready for "long term" profiles.

Your mobo may have a selection for case fan speeds to be controlled off of GPU temps instead of CPU. Have a look.

 

[Stephanie_Sy]

the cooler is pushing or throwing heat inside the case, which might affect GPU temp and heat dissipation...also cable management and airflow might take a pretty crucial place here.

 

[Karadjgne]

If you look at your pc, stock cooler, intake air moves basically sideways. Some gets shoved under the gpu, some gets sucked in by the cpu cooler. Exhaust air is shoved out the side of the gpu and travels up the glass, gets sucked out the exhaust with a good portion of the cpu cooler exhaust.

Constant stream in 1 direction, mostly. All aimed out.

Now you slap in the Arctic duo. You just quadrupled the power of the cpu cooler to pull air. There's a finite volume of air pushed in and the cpu cooler is hogging it. That's going to have an impact on the amount of fresh air the gpu gets. The gpu will pull air from somewhere, so invariably grabs the nearest sources, the slots at the back and its own exhaust.

The only answer is to modify the fan curves, you want to turn up the intakes, higher % at lower temp. If that doesn't help much, then turn the curve way down and remove the pcie slot covers. Let the gpu pull air from there instead of the intake fans.

It's a fine balance of how much lower the gpu goes to how much higher the cpu gets. There is a happy medium. Cpu doesn't care if it's at 70° or 50°, works the same, but the gpu does care if it's getting above 80°.

An intel cpu at idle averages @ 10°C above ambient in a decent airflow case. So if your room temp air is @ 22°C (72°F) you should expect an idle temp of @ 32°C ±. 38°C idle means either your room is hot (100°F) or you have poor airflow through the case. Or your pc is due for a good cleaning....

Can a cpu cooler affect gpu temps? Absolutely yes it can. But not by heat transmitted from cpu cooler to gpu by proximity as you assume, but by changing airflow patterns.

 

[victor70]

The upper GPU sucks up the slightly warm air of the lower GPU, but doesn't have anything to push out its own hot air due to stock cooler. The stock cooler also doesn't direct fan out towards the back (it pushes air down onto the CPU) so hot air just sits and collects between the upper GPU backplate and CPU.

https://www.desmume.online/

 

[Karadjgne]

The upper GPU sucks up the slightly warm air of the lower GPU, but doesn't have anything to push out its own hot air due to stock cooler. The stock cooler also doesn't direct fan out towards the back (it pushes air down onto the CPU) so hot air just sits and collects between the upper GPU backplate and CPU.

The highlighted part is the only correct part.

There's only 1 gpu, so no mention of uppers and lowers, this isn't sli setup.

Air isn't pushed down onto the CPU, that's covered by the heatsink. The air is pushed through the heatsink to the motherboard where either natural convection takes over or pressure from intake fans, exhaust fans, or the heatsink itself removes it from the vicinity in a constant stream. It does not sit stagnant stuck between the gpu backplate and the cpu heatsink.

Sorry.

 

[lordmogul]

Can it affect GPU temps? yes.
Will it always affect GPU temps? no.

In my old system I had my CPU cooler oriented vertically (moving air up instead of front->back), so that it helps pull warm air away from the GPU. The GPU was constantly hitting the thermal limit and be using the CPU cooler to take away the heat, it could hit it's boost clock more consistently.
My current GPU doesn't have that problem, so there it makes no difference.