Case fan

[testcy]

I notice little improvement in CPU temperatures when using a case fan. At the same time the sound increase from the fan is noticeable. I also use two fans for the CPU air cooler. Do you think I should keep or remove the case fan?  

[leclod]

You should keep the fan, replacing the air (and the heat) in the case is important.

Can't you manage the fan speed ?

Every bios can handle a case fan curve, many motherboards provide an app to manage fans in windows (or many of us use Fan Control)

It can't be that a working case fan increases the total noise of a computer.

Edited April 10 by leclod

[testcy]

16 minutes ago, leclod said:

You should keep the fan, replacing the air (and the heat) in the case is important.

Can't you manage the fan speed ?

Every bios can handle a case fan curve, many motherboards provide an app to manage fans in windows (or many of us use Fan Control)

It's a 4-pin case fan, shouldn't speed automatically be managed by the bios? It operates at a higher speed than the two CPU fans, but as a rule three fans don't make more noise than two fans? Should I try to change speed for all fans from normal to silent?

[leclod]

10 minutes ago, testcy said:

It's a 4-pin case fan, shouldn't speed automatically be managed by the bios?

To some extent, but the bios doesn't know which fans you have. They could be 80mm slow fans, 120mm slim fans or 140mm fast fans...

You should adapt the 3 curves yourself.

Also check that the fans are correctly set to PWM (not DC 3pins)

Yes 3 fans make more noise than 2 at the same speed. But 3 fans allows you to reduce the speed of all 3 fans...

Edited April 10 by leclod

[testcy]

22 minutes ago, leclod said:

To some extent, but the bios doesn't know which fans you have. They could be 80mm slow fans, 120mm slim fans or 140mm fast fans...

You should adapt the 3 curves yourself.

Also check that the fans are correctly set to PWM (not DC 3pins)

Yes 3 fans make more noise than 2 at the same speed. But 3 fans allows you to reduce the speed of all 3 fans...

All are 120mm standard fans. Case fan is 600-1350RPM. I don't see where to set PWM, shouldn't this be automatic as they are 4-pin fans?

[leclod]

6 minutes ago, testcy said:

shouldn't this be automatic as they are 4-pin fans?

It depends how old is the motherboard, newer boards recognise pwm fans but I prefer to check.

For example in my bios, on the top left I set that fan to DC

Edited April 10 by leclod

[testcy]

30 minutes ago, leclod said:

It depends how old is the motherboard, newer boards recognise pwm fans but I prefer to check.

For example in my bios, on the top left I set that fan to DC

I don't have these choices, but are there 4-pin fans that are not PWM?

[leclod]

21 minutes ago, testcy said:

I don't have these choices, but are there 4-pin fans that are not PWM?

Not that I am aware of.

But the mobo doesn't know (for sure) you connected a 4 pin fan, you might be using DC fans with 3 pins like I do.

If your board is recent (AM5 or Intel 1851) then you should be fine.

Edited April 10 by leclod

[testcy]

1 minute ago, leclod said:

Not that I am aware of.

But the mobo doesn't know (for sure) you connected a 4 pin fan, you might be using DC fans with 3 pins.

If your board is recent (AM5 or Intel 1851) then you should be fine.

Actually, it is not that recent (LGA 1700).

[leclod]

26 minutes ago, testcy said:

Actually, it is not that recent (LGA 1700).

Like my board, I believe my board recognises PWM fans or it sets PWM by default

I doubt there's no DC/PWM setting in your bios

(I just updated my bios, which resets it and 1 fan was set DC instead of PWM, still works though)

Edited April 10 by leclod

[OddOod]

8 hours ago, testcy said:

I notice little improvement in CPU temperatures when using a case fan. At the same time the sound increase from the fan is noticeable. I also use two fans for the CPU air cooler. Do you think I should keep or remove the case fan?  

Keep it. There's a LOT of reasons, but the short answer is keep it. 

6 hours ago, testcy said:

are there 4-pin fans that are not PWM?

No, but BIOS is frequently an afterthought so don't assume it's too smort
That being said, it *probably* does. Kinda silly not to just send a pulse on the pin to check if there's a connection.
TBH, even if it were operating in DC mode, it's not the end of the world.
 

7 hours ago, testcy said:

but as a rule three fans don't make more noise than two fans?

No. Well, yes, technically but also no. 
Iff you were to run the fans at a target speed, yes, more fans would mean more noise.
But we don't typically target a speed, but rather temperature control of another component, typically CPU/GPU. So, fans get louder as they spin faster, right? But if you can add more fans and get the same temperature spinning slower, you create less sound. In theory you can add enough fans that none of them are noticeable fundamentally illustrating that more fans can easily mean *less* noise. Like, if you needed one fan spinning at 10,000RPM to cool something (which would be ear piercing), you could in theory use 100 fans at 100RPM which would be essentially silent (no, this doesn't work in practice because of several physics reasons, but forgive the thought experiment)

Additionally, not all fans contribute to noise equally. On one end of the spectrum you have the fans buried inside your system: CPU and GPU coolers as well as sometimes even a chipset cooler or, back in the day, RAM coolers (which were never actually useful). Those fans might make just as much noise, but that noise is buried in a loosely sealed box so it is more tolerable. The other end of the spectrum is case fans which are right up next to the openings in that box (or even sometimes mounted on the outside of it if you're me. I had clearance issues...) meaning their noise is tangibly more noticable. The tradeoff is that they are, one way or another, pulling fresh, cool air into the box (when running one case fan, please mount it as an intake on a filtered slot). That means you aren't just relying on the case to essentially act as a wildly inefficient radiator (yes, a properly oriented CPU cooler can push some air out of the rear exhaust, but it's minimal). Instead you are actually taking the hot air and yeeting it away from the sources.