P600s - ditch the rear fan?

[Vertigo]

So I'm trying to get the right fan configuration in a new P600s build, aiming for slight positive pressure to limit dust intake as much as possible.

I have a top-mounted 360 AIO with 3x Noctua NF-A12x25. This is obviously capable of exhausting a great deal of air, depending on the fan speed. Front intake is a pair of Noctua NF-A14.

In an attempt to balance the intake and exhaust and get positive pressure, I'm wondering if it would be better to remove the rear exhaust completely?
With both the AIO and rear exhaust, surely I'm going to have trouble getting positive pressure without running the front fans faster (and thus louder)?

Lastly, I'm just using the basic BIOS fan profiles which are based off CPU speed. I've seen mention on some sites of using Fan Control in Windows to get better control and also potentially key off GPU temps. Is this something people would recommend or just stick to simple BIOS profiles?

Fan configuration and balancing always does my head in

 

[Mcnumpty2323]

Depends on your bios
But mine can set curves based off cpu,gpu
And a load of other things
The other things fair enough a lot of bios won't offer those
As this is a top end board
But you sure you can't choose gpu?
When making a curve
Not just clicking
Silent,medium,flat out etc
Or however yours are named

Software to dial in your curves is OK
But then write down those values
And apply them in a bios curve
Would be the better method
No worries about buggy software then

Edit
Flip rear fan to intake?
Depends how much pressure
Is from 2 x 140 vs 3 x 120 I guess
But flipping rear fan will add more positive pressure

 

[Vertigo]

Yeah my BIOS only appears to offer control based on CPU temp. This is generally ok and how I have things in my current machine as CPU and GPU temp generally rise and lower together when gaming. I just thought the additional control of the Fan Control software might be useful, will have a play.

Flipping the rear fan to an intake is obviously the next step after simply removing it and I might try that.

I don't actually have a GPU in the machine at the moment. Once that's done and the build is complete I may start playing and doing a proper smoke test.

 

[Mcnumpty2323]

Yeah a little experimenting
With the fans doesn't really hurt
Even with same pc case
Other people will be using different fans
Or different fan speed,different gpu etc
Won't be 100% exactly the same as you have
And playing around with the rear fan
Is usually pretty straightforward

 

[Grandmaster Fap!]

I have the P600S with an Arctic 280 AIO in the top and three Arctic 140m in the front, using Argus Monitor to control fan speeds. I have the front fans always spinning slightly faster than the AIO and have hardly any dust inside(very fine particulate is all). The mesh and the filter work really well but you need fans with good static pressure.

 

[Vertigo]

I have the P600S with an Arctic 280 AIO in the top and three Arctic 140m in the front, using Argus Monitor to control fan speeds. I have the front fans always spinning slightly faster than the AIO and have hardly any dust inside(very fine particulate is all). The mesh and the filter work really well but you need fans with good static pressure.

So you're not using a rear fan at all?

My GPU is now installed and I've been playing around with Fan Control to get not only the profiles/curves right but also balance the 2x140 intakes with the 3x120 exhausts. Still not sure what to do about the rear.

 

[Grandmaster Fap!]

So you're not using a rear fan at all?

My GPU is now installed and I've been playing around with Fan Control to get not only the profiles/curves right but also balance the 2x140 intakes with the 3x120 exhausts. Still not sure what to do about the rear.

Nope not using rear, the three 140s create so much positive pressure i dont need another fan. You can feel the air being pushed out the back when gaming.

 

[Drumroll]

140mm fans usually move more air tha. 12mm fans but usually (again) have less static pressure. Fighting a mesh front should be much easier than the radiator the 120mm are facing.
There’s ways to check the airflow in your case, like using smoke from incense sticks, but please don’t cause an accident.
The rear fan should run at very low speed, as if should only help exhaust residual heat. Quite sure it isn’t even needed.
Regarding the fan curves, I only use the motherboard now. Used Octo before, but can’t bother with the extra cables, and being paranoid controlling all. I Su ally find the point where the fans are moving e Pugh air without being intrusive. First temperature for CPU 70C.
Then increase fan speed by 5% and CPU temperature to 75C. Again, another 5% and CPU temperature to 80C. Only when CPU reaches 85C, which is normal for most CPUs now, the fans can go blazing.
Normally, you won’t gain much blazing your fans. If you do, certainly your cooling solution is inadequate or your case airflow is limited.
Having a case 30C from my ear, O can use the T30 at 40% front intake, top exhaust 20% and rear exhaust 25%. 2K rpm profile. Case Fractal North side mesh, 4080 + 7800x3D and Thermalright Phantom Spirit Evo (40%).
Increasing fan rpm by 10% won’t net much. And setting first CPU temperature at a more realistic temperature won’t let the fans speeding up and down (which is more annoying noise wise than a constant rpm, same for pumps) at every CPU spike.
I totally ditched any app to control fans. The only downside is when updating BIOS, I keep the profile saved in an USB drive, so I don’t have to manually enter all that again.
Same for your AIO. Find the PWM range you’re happy with, set and forget. Only if CPU approaches its thermal throttling temperature, then you push your pump to 100%.
Under normal use, I keep the PC as silent as possible. During gaming, as the GPU fans will kick in, increasing 5% or 10% the case fans speed won’t be an issue, but certainly noticeable when idling. Also, with the GPU dumping 300W+ inside the case, even without being heavily loaded, the CPU temperature will increase a bit. The most important thing to note is, if the GPU have decent access to cool air to start with, when under load, it doesn’t need much more air to perform. The extra air will only help remove the warm air, but for that you don’t need twice the fan speed.

 

[Vertigo]

Just spent a couple of hours configuring the fan profiles in Fan Control and have positive pressure at all loads.

At full load the front two NF-A14s need to be at 90% to overcome the three NF-A12x25 exhausts so I think I'm going to put a third NF-A14 in the front so I can lower the speed a touch.

 

[mickyflinn]

Just spent a couple of hours configuring the fan profiles in Fan Control and have positive pressure at all loads.

At full load the front two NF-A14s need to be at 90% to overcome the three NF-A12x25 exhausts so I think I'm going to put a third NF-A14 in the front so I can lower the speed a touch.

You want more air going in then you can exhaust hence giving positive pressure.

Did you reverse the rear exhaust to an intake?

 

[Vertigo]

You want more air going in then you can exhaust hence giving positive pressure.

Did you reverse the rear exhaust to an intake?

Nope, removed the rear fan completely. Problem with reversing it to an intake is there's no dust filter which defeats the object of positive pressure.

 

[Avathar77]

Is there really is a measurable difference in positive vs negative pressure inside a case like P600?

 

[Vertigo]

Is there really is a measurable difference in positive vs negative pressure inside a case like P600?

Surely the specific case doesn't matter? It's just a case of stopping dust being drawn in through gaps which aren't protected by dust filters.