Question CPU tower cooling fan configuration

jaydentkh

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Aug 22, 2017
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Hi all,

I have hesitated for months since I built my PC to ask this question, however I realized I need help as recently my CPU temps have been climbing up to 100 degrees while running 1 single game.

This are my specs:
Asus ROG STRIX Z690-A GAMING WIFI D4
Noctua NH-D15 chromax.black
Intel Core i7-12700K
be quiet! Pure Base 500DX

Because of the design of the motherboard, the Noctua cooler has to be installed facing upwards, meaning to say the fan is pushing air out the top of the case. However as the case I have is a little tiny. I can only fit one fan doing a pull push configuration between the tower fins. The current fan config for the case is 3x120mm fans intake in front and 1x 140mm exhaust at the rear top.

My temps for everything else sits at 80-90 degrees, however my CPU temps registered 100 degrees straight while playing Total War Warhammer 3. I have nothing else open in the background other than discord (not active), steam and Bitdefender.

Is this a fan setup issue, or case size issue, or some other issue that I might have missed? Any advice would be greatly appreciated before I break the bank and buy a larger case (looking at Lian-li)
 

tennis2

Judicious
  • With the M.2 slot above the 1st PCIe slot, it seems like the NH-D15 should fit in the front-to-back orientation. What prevented that?
  • Have you tried removing the cooler, cleaning the TIM, reapplying TIM, and reinstalling the cooler?
    • When you remove the cooler, inspect the TIM to see if it squeezed an excessive amount over the edges of the CPU IHS, or if the cooler base wasn't making even contact with the CPU.
 

geofelt

Titan
Noctua motherboard compatibility chart does indeed show your issue:
https://ncc.noctua.at/motherboards/model/ASUS-ROG-Strix-Z690-A-Gaming-WiFi-D4-5375

It is perhaps a cooler selection issue. The NH-D15s would have been a better selection.
I think you have a airflow direction issue.

I suspect that the top exhaust fan is directing the airflow out the top of the case before it has a chance to enter the cpu cooler.
See what happens if you simply disconnect the top fan.

What is your graphics card?
The front 120mm intakes should be sufficient intake airflow unless they are operating at a low rpm. I would think you you would want 1200 rpm.
Increasing that rpm would help cooling at the expense of noise.

You could also experiment with disconnecting the rear exhaust.
The theory is that all of the front intake is going to exit somewhere, taking component heat with it. Exhaust fans are there mostly to direct airflow direction.

You have a nice case and I would be reluctant to change it out.
 
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Because of the design of the motherboard, the Noctua cooler has to be installed facing upwards, meaning to say the fan is pushing air out the top of the case. However as the case I have is a little tiny. I can only fit one fan doing a pull push configuration between the tower fins.
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It sounds like the CPU cooler is drawing the hot exhaust air out of the GPU directly into itself. That's essentially raising the ambient air temp for the cooler by 20 degrees...maybe upwards of 50 degrees or more while gaming. Big air coolers like that are just as efficient at pumping heat into a CPU from the surrounding air as they are at taking it out.

With a similar situation to that in a small mATX case I found the solution was to reverse airflow to what's customary. That is: arrange fans to blow cool air into the CPU fan (also reversed) from top/rear and then exhaust the hot air from GPU and CPU from the front. It's not ideal...although the flow of war air across my keyboard is nice in winter :) and may not work for you but may be worth trying.
 
Last edited:
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tennis2

Judicious
Noctua motherboard compatibility chart does indeed show your issue:
https://ncc.noctua.at/motherboards/model/ASUS-ROG-Strix-Z690-A-Gaming-WiFi-D4-5375
Begs the question: can the plastic VRM shroud be removed?

I suspect that the top exhaust fan is directing the airflow out the top of the case before it has a chance to enter the cpu cooler.
See what happens if you simply disconnect the top fan.
Or move it to the rear exhaust location.
 

jaydentkh

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Aug 22, 2017
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Hi everyone,

Thanks for the quick replies, had a screaming baby to handle on my part. I forgot to add that I had one rear fan and one front-top fan that were disabled, I tried reenabling the rear fan now to see if it helps.

@tennis2
yeah as geofelt mentioned, it is the plastic VRM that is blocking, I have tried installing the cooler the typical right to left manner but it just doesn't have the height clearance. I did try reapplying the cooler once, the temps remained around the same. No idea if the plastic VRM can be removed.


@Phaaze88
Its like a few cores (3/4), the rest are sitting at near 95. I need to try triggering it again to get the numbers right. GPU is Gigabyte GeForce RTX 3080 Aorus Xtreme.
Here are the photos:
Front fans: View: https://imgur.com/v1LzycD

Top fans: View: https://imgur.com/6kFlJSc

Overall view: View: https://imgur.com/UnFVFv9

Top view (To see the front fan is disabled): View: https://imgur.com/z9Mrws9


@geofelt

It is perhaps a cooler selection issue. The NH-D15s would have been a better selection.
I think you have a airflow direction issue.

The NH-D15s was unfortunately non-existent here when I first built this PC last year.

I suspect that the top exhaust fan is directing the airflow out the top of the case before it has a chance to enter the cpu cooler.
See what happens if you simply disconnect the top fan.

I will give this a try when I can.

What is your graphics card?

Its Gigabyte GeForce RTX 3080 Aorus Xtreme.

The front 120mm intakes should be sufficient intake airflow unless they are operating at a low rpm. I would think you you would want 1200 rpm.
Increasing that rpm would help cooling at the expense of noise.
You could also experiment with disconnecting the rear exhaust.
The theory is that all of the front intake is going to exit somewhere, taking component heat with it. Exhaust fans are there mostly to direct airflow direction.

So you are recommending I raise the RPM for the intake fans and remove the exhaust fans? I actually never tried that before, usually I see recommendations include intake and exhaust fans.

You have a nice case and I would be reluctant to change it out.

Yes I thought so too, would hurt to have to buy another bigger case just because, big,

@drea.drechsler
I thought so too, but I really want to get my current setup working before considering switching to AIO.
 

Phaaze88

Titan
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This looks like a cooler mounting issue to me, and nothing more. What's the max and average cpu package power while in Warhammer?
Run HWINFO in the background. When you start playing, click HWINFO's reset button(that clock icon) and play for a few minutes - or maybe the length of a quest or mission? I don't know how long those go for.
When finished, find Cpu Package Power. It'll have a '⚡' next to it. Report back what the max and average are.
 
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I thought so too, but I really want to get my current setup working before considering switching to AIO.
One of the major benefits to liquid cooling is it's ability to move the heat away from it's source before exhausting it and/or so it can get the benefit of cool external air. That often makes it the ideal solution for difficult cooling situations if there's a good location for mounting the radiator.

Fortunately, it looks like your case is perfect for front mounting up to a 360mm radiator to bring cool outside air across it instead of the hot GPU air. That will leave a clear path to the top and rear fans to exhaust both the CPU and GPU's heat.
 

jaydentkh

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Aug 22, 2017
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@Phaaze88
I will test tomorrow when I get to play, will keep you updated.

@drea.drechsler
Yes I was all for air cooling while hearing stories of leaky pumps from some of my friends. Again the Noctua I got wasn't cheap, really want to get it running if possible.
 
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Yes I was all for air cooling while hearing stories of leaky pumps from some of my friends. Again the Noctua I got wasn't cheap, really want to get it running if possible.
Oh, it's running...working great from the sound of it. The problem isn't the cooler (it's truly great), the problem is giving it feed air that's not pre-heated by the GPU.

While there's always an exception the risk of leaky systems is mostly an issue of custom loop systems, the ones you have to pipe and fit yourself. AIO's...modern AIO's...have come a long way with very good sealing of fittings in the system. The biggest problem is the build up of anaerobic's clogging heat plate microfins in one or two years. That's mostly limited to a few mfr's (MSI in particular comes to mind) that have had problems with that so be sure to pick a good brand, of which there are many out there. It doesn't have to be an expensive RGB rig either.
 

Vic 40

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Why is that one top fan blowing air in? What happens if you disconnect it and just use the remaining two fans in the back to exhaust air?
Or you could also use the back fan as extra intake (flip it around) and use the two top fans solely for exhaust, think this will be a better option than the configuration you use right now.
 
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jaydentkh

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Aug 22, 2017
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Hi all,

Sorry for the late replies, covid hit the baby so no games for these few days. Managed to give it a couple hour try on Total War Warhammer 3 to test the temps after enabling the rear exhaust. So now I have 3 120mm intake and 2 140mm exhaust. So far the temps hover around 90 degrees, with max at 93 which I assume it is good? I am playing at Ultra settings if it matters.

@drea.drechsler
Yeah I have seen how AIOs are rising fast in popularity nowadays, back when I was still in school saving up for my first prebuilt they were saying AIO leaks or its bad your motherboard will go kaboom. Will give them a shot on my next build.

@Vic 40 heya, the fan you are indicating is off, I was experimenting with it but the temps went haywire just idling, hence I just disable it.
The rear intake suggestion, I thought of it before but will it interfere with the Noctua airflow? I was concerned how the top exhaust and the rear intake will have some form of conflict but I am no expert. Haven't give it a try yet.

@Phaaze88
I will give it a try next. Am I expecting better temps? If so, does this mean there is something wrong with the whole build? Like too small a case, or fan airflow not optimal?
 

geofelt

Titan
I think the rear exhaust has largely fixed your problem.
So long as you can keep the max at less than 100c. you will not throttle.
Your max turbo may be limited a notch or two, but these new processors are so crazy fast that you will not notice that.

How is your gpu temperature?
Normally, that should keep at about 80c. under load.
 

Phaaze88

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Am I expecting better temps? If so, does this mean there is something wrong with the whole build? Like too small a case, or fan airflow not optimal?
Yes.
If it improves by... say, 6C or more, then it can be chalked up to the D15 not getting enough cool air through it in the vertical position.
If it doesn't improve, or barely changes, then the guilty party is the cooler mount, or the motherboard settings are too aggressive - i.e. MCE/Load Line/Vcore.
 

Vic 40

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@Vic 40 heya, the fan you are indicating is off, I was experimenting with it but the temps went haywire just idling, hence I just disable it.
The rear intake suggestion, I thought of it before but will it interfere with the Noctua airflow? I was concerned how the top exhaust and the rear intake will have some form of conflict but I am no expert. Haven't give it a try yet.
Don't think it will interfere with the airflow, at least i think it will be better. Swapping the back fan to intake and that top fan to (working) exhaust shouldn't be too much trouble and do suggest to try it.
 

Karadjgne

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A fan works by moving an angled blade through air. As the blade moves, it creates a void, a low pressure area behind it. The byproduct being the higher pressure pushed outwards by the angle of the blade. Get multiple blades and spin them faster, creates a larger and lower pressure at the front of the fan.

Nature abhors a vacuum, so any air in the vicinity of said vacuum will move to fill the void. That creates airflow in a case.

If you look at the cpu cooler, it's got 1 fan pushing air up, but the rear exhaust is right next to it, perpendicular, which is creating a large void at one edge of the cooler. Figure a good portion of cooler pulled/pushed air is going sideways, right out the back, before it even gets chance to go through the cooler fully.

Change both top fans to exhaust, disconnect the rear exhaust and see what happens to temps. If you use the rear as intake, keep rpms low, just enough to help feed the cooler fan, not enough to interfere with the airflow through the heatsinks.
 

Kona45primo

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Jan 16, 2021
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I would flip it around a bit, D15 blowing onto the back of the gpu, top fan flipped to intake. . . Keeps the cpu and gpu cooler.... Or get a bigger case. Lian Li meshcool II should keep everything cooler.
 

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