Question case fan curve/fan recommendation

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Nov 22, 2021
Hello friends been a while ,i have a question about bios fan curves and fans/case in general , so the issue is my gpu is always running warmer than i like, i know 75 isnt hot im more concerned that MSI after burner has the fan speeds at 82% , i tried my own fan curve which ran the fans at 75% in afterburner for the gpu and it actually got warmer (77) like 75% was not enmough speeds to kep the card cooler
im horrible at fan curves but im trying to learn and if i can fine tune the case airflow the gpu should run cooler as well unless the case/fans are just terrible themselves, so i'll give you my specs again.

r5 3600
msi b550m pro vdh wifi motherboard
asus ko 8gb 3060ti
seasonic 850 focus gold
32 gigs trident 3600 cl 16
case is a coolermaster master box mb311L
my case fans are coolermaster argb 4pin for top (2 intake) rear(1 exhaust)
the fronts are 3 pin that came with the case (2 intake) so i have 4 intake 1 exhaust thats not including 2 fans on gpu, 1 fan on cpu, 1 psu

so here are the curves i have in the bios and the sensors for them
cpu fan (stock wraithn cooler) 0-55 degrees its at 50%, 65 degrees is 75%, 75 degrees is 100% (1 fan) SENSOR = cpu core
pump (4 pin top intake) 0-60 at 50% , 65 degrees is 75%, 75 degrees is 100% (2 fans) SENSOR = system
front (3 pin intake) 0-60 at 6.12V , 65 degrees is 9.12V. 75 degreesis 12V (2 fans) SENSOR = system
rear (4 pin exhaust) 0-55 drees is 50% , 65 degrees is 75% , 75 degrees is 100% (1 fan) SENSOR = CPU (so when cpu warms up it exhausts at the same rate as cpu fan cools as its directly inline with cpu)

i changed all these today as i didnt realize when i updated the bios i had all the fans on cpu core and the constant fluctuation with cpu was driving me nuts so i put them all on system besides exhaust, I dont know if system sensor is okay to use, i dont know if my settings are good , i dont even know if the fans are optiomal /good they are cheap, cpu stays cool at 60-67 , i know the case isnt the best either but im just trying to ball on a budget until after i get my surgery then i'll be going to a 5800x3d, 3080/3090 i dont want to go am5 or 40's series but that discussion is for later.
to summarize im just trying to get the best cooling/temps i can for right now, looking to improve fan curves to provide optimal flow but i dont know how to even tell if the flow is good , recommendation on better case fans if i need to upgrade them and a case (this can be put off as i stated i will be upgrading after surgery which is new case/mobo/cpu etc etc ) but a recommendation for later would be nice i weas looking att he phantex p400. i cant upload pics or i'd take pics of the fan curves in the bios. i am going with a noctua U12 for this cpu when i build the upgrade (well have it built)



Nov 22, 2021
It’s not just number of fans, it’s placement and what they do. Try two front intake, two exhaust rear and top rear, disconnect the top one closest to the front.
Only have room for one in the rear, I tried none on top earlier and it made the sys sensor get hot so all the car fans were at 75% which sounded like a turbine engine lol
the rear fan next to the cpu cooler is exhaust, the top 2 are intakes, the front 2 are intakes they all have pretty much the same exact fan curves the bios, I see all these other cases with like 9+ fans how are they able to make theirs work and I can't use 5 without them canceling each other out? I did try to use the pc without the tops running earlier after recommendation and the system sensor went to 64° (what I have the case fans ran off of) which had the case fans at 75%, the system sensor don't reach 60° with them on, ship m literally just trying to get an idea of how they should be setup in the case to get the best airflow I can with what I have,, but phaaze is right in alot of points, my gpu doesn't have much breathing room between the fans and the psu bay top
The problem with this arrangement as I see it is the top rear fan as an intake is just going to have its air sucked out from the rear exhaust fan and the top front fan is pushing down on the front intakes. While I can't say for certain what'll happen, I'm pretty sure that's not good for the airflow in the front.

As I understand it, air flow that follows basically a single direction as much as possible is ideal.

EDIT: One thing I also suggest doing is remove the other expansion slot cover. The video card needs as much air it can breath and that's not helping.
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Maybe a few basics to help understand. Removing heat requires air FLOW. You really have three very similar air flow control systems, and each has a sensor for the TEMPERATURE of the hot item, plus a fan (or more) to move air. Each system alters its fan speed according to the temperature of the item it is trying to cool.

The main "common" system is the set of five fans that blow air through the case. They pull air in at the front pair and top pair as you have it set up now, and remove warmed air out through the only exhaust fan at rear. In general, it is best to have intake and exhaust fan capacities balanced so they can help each other. Many (including me) argue that ALMOST balanced is best IF you can arrange to have just slightly more intake capacity than exhaust. That is only because such an arrangement can mean the air pressure inside your case is slightly higher than outside, so air LEAKS at cracks cause flow from inside to out. That means the only air flow into your case must come though the dust filters on the intake fans, and hence you get less dust build-up inside. However, that's fine detail that may be hard to achieve. The MOST important item is total air FLOW.

In your case, OP, with five fans there will never be exact intake / exhaust balance. The available fan locations limit you to two in the front. By far the most common arrangement is INTAKE at the FRONT, EXHAUST at the REAR, and usually exhaust also at the TOP. With your situation this would give slightly more exhaust capacity than intake, so the interior of the case will be at a slight negative pressure and air can leak in. But it's more important to use as many fans as you can, so keep those five, but set the top fans as exhaust.

We should recognize that each of the three automatic cooling systems tries to keep its respective TEMPERATURE at its setting, and will change its fan speed to achieve that. So, when you alter the flow of air though the case, you do NOT necessarily see a big temperature change. But you WILL see changes of the fan SPEEDS it uses to achieve those temperatures.

Recognize also that both the CPU cooling and GPU cooling systems use that general case air. It is NOT "hot" - just a few degrees warmer than the room air. So general case cooling by those five fans will have an effect on what the CPU and graphics card fans have to do to meet their temp targets.

I would recommend that you set all three cooling systems (CPU, case, and graphics card) to their DEFAULT automatic temperature control operations. Let them do their respective jobs and use the info (below) to decide whether other settings are needed.

Now, hotaru.hino has pointed out a problem at the top if they are exhaust fans. With both intake (front) and exhaust (top) at the top front corner of the case, the air may simply "short circuit" though those two fans and the case gets little benefit from their operation. In that situation you may actually get better air flow though the case by disconnecting the Top Front exhaust fan so that the top intake fan's air DOES blow through the case. Although you are using one less fan, it may actually be better for air flow. The only way to tell which way is best is to try and see. Now, how would you know? Set it up with your five fans as recommended. Make notes of the case (System), CPU and GPU temperatures AND of the SPEEDS each fan system is running. Do this for several workload conditions. Shut down, disconnect that top front fan, and re-do all those tests. You may find that one condition gets you very slightly lower temps and slower fan speeds.

Once you have found the better fan arrangement you can return to your thoughts of what the fan speeds should be. Don't forget that, when you force any fan to run slower to generate less noise, you also force it to remove LESS heat and thus the temperatures will be warmer. And the opposite, of course, if you are trying for cooler operating temps. I suggest you DO use the automatic temperature control systems, and not set fixed fan speeds. That way the systems will adjust their operations as your workload changes. Just be sure that at max workload the fans still are not quite at their max speed, so there is some reserve cooling capacity for higher heat events.
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Paul Anderegg

Aug 30, 2012
One thing to keep in mind with Nvidia GPUs is the speed bins. As the temps increase at specific temperatures the GPU will throttle down like 15MHz at a time when against it's power limit. Assuming your card can be maxxed out undervolted that way, you might want to run Heaven at 100% fans and slowly manually lower fan speed 5% at a time in Afterburner and see what the max temps the card gets too at each fan %, and the corresponding boost clock speed. For my 3080Ti that likes to toast aroud 70c at max fan and max watts, anything from around 85-100% ends up givig me the same boost clock speed, so I set my fan curve to go 85% at 69C and then 100% at 80c. Lowering the GPU fans from 3000rpm to 2500rm makes an audible difference, not super quiete, but enough I feel I got lower noise and no performance hit.