Optimal RPMs for my 13 fan setup?

[HungryHamster]

I recently built a new gaming PC in the Corsair 5000t and it has 13 fans (3 front intake, 3 side intake, 1 rear outtake, and 6 on the radiator in push/pull configuration). 10 of the fans are Corsair QL fans and 3 (on the top side of the radiator) are ML fans. I currently run all of the fans at a fixed 75% except I have my 6 radiator fans set to the "performance" preset in the Corsair iCUE software.

 

I'm wondering if I should be running at all these fans at the same speed or at different speeds? If different, what percentage would you recommend for each of the fans? For instance, would it be better airflow to have my 1 rear outtake at 100% and my 3 front and 3 side fans set to 50%?

 

Any input would be appreciated.

[vertigo220]

Whatever speeds provide the cooling needed at the quietest level possible. Other than that, with that setup, doesn't really matter. Without knowing the fan sizes/models I can't say for sure, but odds are you'd have to really try to create a negative pressure situation, and rear fan speed isn't going to make a huge difference whether it's at 50% or 100%. Intakes are much more important, since they're the ones actually bringing fresh, cool air in. The rear is just helping move the air in a current/stream, but think of it more as a training wheel than a main one.

[OhioYJ]

Personally I would set them all up on a fan curve. I don't use a static speed, but have my fans speed up as needed. (Typically using CPU temp). The fans don't need to spin so fast with the machine at idle. Might as well only have it be "loud" when it needs to be.

[vertigo220]

Just now, OhioYJ said:

Personally I would set them all up on a fan curve. I don't use a static speed, but have my fans speed up as needed. (Typically using CPU temp). The fans don't need to spin so fast with the machine at idle. Might as well only have it be "loud" when it needs to be.

Correct. My point is that it to run it as low/quiet as possible to maintain temps, so very low at idle and higher under load as temps increase, but at each "step" only as high as necessary to keep the temps reasonable.

[HungryHamster]

4 minutes ago, OhioYJ said:

Personally I would set them all up on a fan curve. I don't use a static speed, but have my fans speed up as needed. (Typically using CPU temp). The fans don't need to spin so fast with the machine at idle. Might as well only have it be "loud" when it needs to be.

I might look into doing that. On a previous build I had a fan curve and it was really annoying to have my fans ramp up all of a sudden because the CPU jumped to like 60c while opening a PDF or something.

[vertigo220]

1 minute ago, HungryHamster said:

I might look into doing that. On a previous build I had a fan curve and it was really annoying to have my fans ramp up all of a sudden because the CPU jumped to like 60c while opening a PDF or something.

This is another reason to keep the speeds as low as possible along the curve. Heat is only a concern once you get up to at least 85-90c, so you can have them barely spinning up to something like 60, then at like 40% from 60-80, then 60% at 85 and max at 90-95, or something like that. People tend to think they have to keep their system cool all the time, but that's not the case. It can run a bit warm without hurting anything and be quieter as a result. You can also see if the control software will allow you to set a delay, so it will only ramp up if the temps stay above the threshold for a certain amount of time. I haven't had time to really play with it yet, but Fan Control looks like it can do this via hysteresis.

[Ralfi]

1 hour ago, HungryHamster said:

On a previous build I had a fan curve and it was really annoying to have my fans ramp up all of a sudden because the CPU jumped to like 60c while opening a PDF or something.

Yeah you need to note when this happens - these are burst spikes that can be really annoying. When you know how high these bursts in temp go, then you can set your idle range for your fan curves to cover them (I have my idle fan curve flatlined at ~650RPM up to 60C or 65C for eg. but typically, my CPU stays at low 30s in winter & mid-high 30s in Summer). 
 

Depends on the case & fans at how low RPM that idle ‘curve’ can be.

[thrasher_565]

6 hours ago, vertigo220 said:

This is another reason to keep the speeds as low as possible along the curve. Heat is only a concern once you get up to at least 85-90c, so you can have them barely spinning up to something like 60, then at like 40% from 60-80, then 60% at 85 and max at 90-95, or something like that. People tend to think they have to keep their system cool all the time, but that's not the case. It can run a bit warm without hurting anything and be quieter as a result. You can also see if the control software will allow you to set a delay, so it will only ramp up if the temps stay above the threshold for a certain amount of time. I haven't had time to really play with it yet, but Fan Control looks like it can do this via hysteresis.

heat is never a concern with pc build really laptops shur but pcs nop. no evadances that says ruining it at its tj max is bad i think they would still warranty it if something did happen. thow thermal throttling you lose preformaces but still wont heart it.

[freeagent]

Get a case where you don’t need 13 fans?

[vertigo220]

5 minutes ago, freeagent said:

Get a case where you don’t need 13 fans?

Somewhat counterintuitively, more fans can actually be quieter. 13 fans running at 1500 rpm will move more air and make less noise than 3 fans running at 2500 rpm.

[freeagent]

29 minutes ago, vertigo220 said:

Somewhat counterintuitively, more fans can actually be quieter. 13 fans running at 1500 rpm will move more air and make less noise than 3 fans running at 2500 rpm.

Oh yeah, I have been on both sides of the spectrum using industrial fans.

[thrasher_565]

each fan added to the total db but how to calculate that i dont no. but there are other factors to asoming not all fan holes are equal. im gonna have a banana amount of fans in my build... 20 fans just for the 5x 560 rads...