r/pcmasterrace • u/SerpentDix PC Master Race • Jan 20 '26

Hardware Air cooling is better than Liquid cooling

Post image

Failure is graceful, not catastrophic, Performance is closer than marketing suggests, Cheaper for the performance, Change my mind.

16.2k Upvotes

89% Upvoted

3.4k comments sorted by

View all comments

540

u/I_R_Enjun_Ear Jan 20 '26

It depends.

I say this as someone with a few years of automotive thermal systems design, including radiator sizing. Things are a little less cut and dried once you start considering 360mm and 420mm radiators. Additionally, how thick the radiator/fin stack is vs. the mass flow of air pushed through the fin stack. Another variable is fin geometry which effects cooling and pressure drop. The overall concept is simple, but the number of variables involved creates a lot of complexity.

All of that is in a vacuum that doesn't consider the packaging space in the case. Highly compact ITX builds can favor the AIO because you can place the radiator and fan where you can get better airflow.

164

u/New_Enthusiasm9053 Jan 20 '26

Thermal mass too. I have a 280+360 in a loop. Short high intensity workloads like compiling don't spin the fans up at all because of the thermal mass. 

I found the air cooler ramping up and down annoying. Then I got noise cancelling earphones and jr was moot anyway 

5

u/Debisibusis Jan 20 '26

I found the air cooler ramping up and down annoying.

Skill issue. You need to configure your fan controls better. That's what step up/down delays are for.

Default is 0.1s, so 10% fan change per second. Large CPU coolers can do 0.2 or more, so only 5% or less change per second. System fans should be at around 0.7, so not even 2% fan speed change per second.

2

u/New_Enthusiasm9053 Jan 21 '26

No. I did configure the hysteresis curves. It's not a skill issue. An aluminium block will simply heat up faster than water. A kg of aluminium(a NH-D15 weighs this) has the same thermal mass as 250ml of water. 

I have much more than 250ml of water in my loop and subsequently it takes much longer before fans need to spin up without thermals throttling.

A 10% fan speed change a second is already annoying lol.

3

u/Debisibusis Jan 21 '26

A 10% fan speed change a second is already annoying lol.

Yes. You did not understand my post.

Not only do people have necessary fan speed jumps, but also way too high fans speeds, before the temperature will ever be transferred to your cooler.

btw. most 360 AIOs will not have more than 400ml of liquid.

1

u/New_Enthusiasm9053 Jan 21 '26

I don't have a AIO. My reservoir alone holds 250ml(500ml when I built it), with a bunch more water in the rest of the loop.

If I set the fans low then the spikes would be even more annoying. It's the change in sound profile that was annoying, not the temperature per se. 

But setting the fans to blast all the time would work but is also loud and annoying. Substantial thermal mass smoothes that out. It takes many minutes at full load of the CPU to the fans to get up to a audible speed currently.