Do Fans need to be attached to case and CPU to cool or do you just need case fans?

[Dan Flame]

Hello! I wanted to know if fans on a computer have to be on a CPU and the case to cool or do you not need fans on the CPU and just the case?

[Semper]

If you have a heatsink on your CPU, it will need a fan, unless it's purpose built to be a passive cooler.

If you have your computer in a chassis (as opposed to an open air bench, for example) chassis fans are highly encouraged. Poor airflow will lead to increased temperatures. Increased temperatures will result in throttling to protect itself. Throttling will lead to lower performance. As a whole, undue heat stress will add to the wear and tear of temperature-sensitive components.

[Bombastinator]

There are fanless “passive” cpu coolers.  Zero fan makes two that I know of.   They tend to be very large and have fairly low TDP.  Cpu coolers designed to have no attached fan have been designed.  They’re set up to deal with much lower velocity air movement so their fins tend to be a lot farther apart.  Means they need more space for the same surface area.

[Demonic Donut]

If you oversize your CPU cooler and have good case flow you can ignore CPU fans. I did it on my old 3570 with a Noctua D15

[Fatih19]

2 hours ago, Semper said:

If you have a heatsink on your CPU, it will need a fan, unless it's purpose built to be a passive cooler.

If you have your computer in a chassis (as opposed to an open air bench, for example) chassis fans are highly encouraged. Poor airflow will lead to increased temperatures. Increased temperatures will result in throttling to protect itself. Throttling will lead to lower performance. As a whole, undue heat stress will add to the wear and tear of temperature-sensitive components.

Yes, I experienced this firsthand. I have a 2700X using the Wraith Prism in a Cooler Master Q300L, a micro ATX case. Previously, I had 2 intake and 1 exhaust which results in idle temperature of 50-60 C. Which is awful. I then doubled the fans to 4 intake and 2 exhaust and I can now reach idle temperature of high 30 and mid 40. Also to note here is how you tune your fan curve. More aggressive fan curves would result in better temperature but leads to higher noise (although this can be avoided by buying high-end silent fans).

[LogicalDrm]

Most optimal setup is fan on CPU cooler, one intake and one exhaust. If you must, then just one exhaust, but this tends to cause high temps. Recommended setup is fan on CPU cooler, 2x intake and one exhaust.