Case fan dilemma - FD Define Mini C TG - GPU Runs hot

[Laz_]

So, my PC is in the Fractal Design Define Mini C TG.
I have the following problem: I can't put my sidepanel back on, because I don't have enough air flowing under the VGA. GPU runs around 76-85℃ when under load, fans spin up, and they get loud with the glass panel on. Without the sidepanel they are barely audible under load. My front panel intake is also restricted, because of dust filtration and noise insulation. I quickly janked image of the situation.
I think the problem lies in the fans... (Feel free to correct me) The ones I have now are pretty crappy and loud. They suck, because the don't suck, if you now what I mean.
Could you please suggest some 140mm black fans, which would suit this build?
Thank you for your suggestions, in advance.

[Bombastinator]

I don’t know fan models, but I can think of some general specs:

you’ve got air restriction up front. Something high static pressure.  Maybe ones designed for liquid coolers.

 

alao it looks like it might be an overpressure case.  Taking the slot covers off the rest of the pci slots in back may help unless they’re already grillwork.  Give your hot GPU exit air someplace to go.

 

 An extreme and possibly not so good move would be to make it high overpressure by taking off the plates and flipping the back fan to “in”.  That would force all the case air out the pci slot cover area.  It could overheat your CPU though.  Also no filter on the back.  All kinds of problems.

[Laz_]

1 minute ago, Bombastinator said:

I don’t know fan models, but I can think of some general specs:

you’ve got air restriction up front. Something high static pressure.  Maybe ones designed for liquid coolers.

 

alao it looks like it might be an overpressure case.  Taking the slot covers off the rest of the pci slots in back may help unless they’re already grillwork.  Give your hot GPU exit air someplace to go.

 

 An extreme and possibly not so good move would be to make it high overpressure by taking off the plates and flipping the back fan to “in”.  That would force all the case air out the pci slot cover area.  It could overheat your CPU though.  Also no filter on the back.  All kinds of problems.

I have swapped the PCI covers to some Cooler Master one, because the vents are much bigger. I will remove them, and check the temps. Wish me luck.

[AndrewB121]

I have basically the same case. I would recommend a couple of high static pressure fans on the front to push air through the case. I'm currently using Corsair ML140s. 

 

You could also solve the issue by flipping the PSU so that it draws air from inside the case (right where the hot air pocket is) and expels it out the back, effectively bypassing the vga slot issue. The PSU would run a little hotter but it wouldn't be much of an issue, and it would keep air flowing through past the gpu. 

[Bombastinator]

5 minutes ago, AndrewB121 said:

I have basically the same case. I would recommend a couple of high static pressure fans on the front to push air through the case. I'm currently using Corsair ML140s. 

 

You could also solve the issue by flipping the PSU so that it draws air from inside the case (right where the hot air pocket is) and expels it out the back, effectively bypassing the vga slot issue. The PSU would run a little hotter but it wouldn't be much of an issue, and it would keep air flowing through past the gpu. 

For what it’s worth I like this PSU flipping idea better than mine.  PSUs can handle heat pretty well.  Only issue I can think of might be if the PSU is really overpowered and is on some sort of silent mode so it doesn’t spin it’s fan unless the heat is high.  With a big enough PSU or high enough silent temp setting it might not get hot enough for the PSU to spin its fan in which case you get nothing.

[AndrewB121]

2 minutes ago, Bombastinator said:

For what it’s worth I like this PSU flipping idea better than mine.  PSUs can handle heat pretty well.  Only issue I can think of might be if the PSU is really overpowered and is on some sort of silent mode so it doesn’t spin it’s fan unless the heat is high.  With a big enough PSU or high enough silent temp setting it might not get hot enough for the PSU to spin its fan in which case you get nothing.

Yeah I think flipping the PSU is the way to go. It should immediately solve the airflow under the GPU issue.

 

Even if he has some ultra-low-noise PSU he could just turn the fans up a tiny bit, it'll still be pretty quiet.  

[Laz_]

3 minutes ago, Bombastinator said:

For what it’s worth I like this PSU flipping idea better than mine.  PSUs can handle heat pretty well.  Only issue I can think of might be if the PSU is really overpowered and is on some sort of silent mode so it doesn’t spin it’s fan unless the heat is high.  With a big enough PSU or high enough silent temp setting it might not get hot enough for the PSU to spin its fan in which case you get nothing.

I will give it a try. My PSU is a 750w EVGA unit, with the eco mode turned on. But when the system is under load, the fan kicks in, and that's when the "pocket" effect starts to appear. So this might a solution.

[Bombastinator]

2 minutes ago, AndrewB121 said:

Yeah I think flipping the PSU is the way to go. It should immediately solve the airflow under the GPU issue.

 

Even if he has some ultra-low-noise PSU he could just turn the fans up a tiny bit, it'll still be pretty quiet.  

If it’s got a variable setting that would work best.  A lot of them are just “on” or “off” though.  From the sound of @Laz_’s last post the gpu ramping up kicks on the PSU fan so it might work well for “on” anyway.

[Laz_]

 Just opened the PC, turning the PSU. Let's see.

[Laz_]

1 hour ago, Bombastinator said:

If it’s got a variable setting that would work best.  A lot of them are just “on” or “off” though.  From the sound of @Laz_’s last post the gpu ramping up kicks on the PSU fan so it might work well for “on” anyway.

Nope. I flipped the psu, and the PC is still friggin loud. The GPU temps are constant 75C under load, and the GPU fans a trying to compensate by wramping up.
At least it was worth a try. The hot air pocket is still present. 
So what now? New intake fans?
 

[Bombastinator]

55 minutes ago, Laz_ said:

Nope. I flipped the psu, and the PC is still friggin loud. The GPU temps are constant 75C under load, and the GPU fans a trying to compensate by wramping up.
At least it was worth a try. The hot air pocket is still present. 
So what now? New intake fans?
 

Did you try it with eco off?  How many settings are there for it? 

[For Science!]

9 hours ago, Laz_ said:

 

You have a testable hypothesis, you should remove the front panel of the define c ( iirc) and if your gpu temps dont improve no amount of fan improvement will hekp.

[Laz_]

8 hours ago, Bombastinator said:

Did you try it with eco off?  How many settings are there for it? 

There's an always-on mode, and I turned it on, and it didn't help sadly. 

[Laz_]

1 hour ago, For Science! said:

You have a testable hypothesis, you should remove the front panel of the define c ( iirc) and if your gpu temps dont improve no amount of fan improvement will hekp.

I took the panel off, and the temps dropped by 8-10C. But the fans are still weak. When I put my hand in the case (when the side and front panel is off) , and the "breeze" is barely noticeable. I really have to crank em' to insanity to achieve a slightly better flow. 

EDIT: I also removed the front dust filter. 

[Bombastinator]

50 minutes ago, Laz_ said:

There's an always-on mode, and I turned it on, and it didn't help sadly. 

Ok.  That’s weird.  
Implies either airflow isn’t actually the problem or that PSU can’t be made to improve airflow.  @For Science! has a good idea.  If that doesn’t work it’s not an airflow issue.  At least not one you can fix.

[Laz_]

These are my temps with the front panel off, the PSU (fan) flipped down and the front fans cranked to 900rpm. (when I stopped the front intake fans, the vga wasn't loud, the front fans make most of the noise) 

 

(I know, it's not a fancy screenshot. xD) 

[Bombastinator]

Hmm. Not seeing any temps.  Noise description says it’s airflow issue after all.  I wish that side panel wasn’t glass.  If it was metal you could just cut a 120mm hole in it, install a fan and fan grill, and keep going.  I hate glass side panels.

[For Science!]

8 minutes ago, Laz_ said:

 

Solution 1: Get static pressure oriented fans, (e.g. Noctua NF-F12 Chromax, EKWB Vardar etc etc)

Solution 2: Switch to Meshify C

Solution 3: Solution 1 + Solution 2

[Bombastinator]

And the pic for GPU is up.  Those fans are 43%. That’s less than half speed (barely). I agree with @For Science!. Case suckage.

[Laz_]

38 minutes ago, For Science! said:

Solution 1: Get static pressure oriented fans, (e.g. Noctua NF-F12 Chromax, EKWB Vardar etc etc)

Solution 2: Switch to Meshify C

Solution 3: Solution 1 + Solution 2

Yeah, that's gonna work. But Noctua doesn't make an NF-F14. Why? What the frick. I would instantly buy that.
Are Artic P series fans any good? P14 PWM for example?
I heard, that Corsair's ML140 Pro-s a loud? Is this true?

Or NF-A14 Chromax? Does that  fan have enough static pressure?

[For Science!]

32 minutes ago, Laz_ said:

-

Oh right, you wanted 140 mm, use NF-A14, I use them in my office build in my MeshifyC. https://noctua.at/en/nf-a14-pwm-chromax-black-swap

 

I used ML140's before, imo louder than NF-A14 at an equivalent airflow, so I would choose Noctuas. No opinion on Arctic P.

[Laz_]

Okay. If the NF-A14 has great static pressure I will pull the trigger. I wil buy one, put it in front of the VGA. Will see if that improves temps. 

[Bombastinator]

Agh.  I didn’t realize the 140 vs 120 thing was on this thread.  Derp.  120s will have more total static pressure than 140s.  The bigger the fan area the worse static pressure. In theory at least.  3 120mm high static pressure might yet do it.  Maybe the 140 will be enough.

[Laz_]

12 minutes ago, Bombastinator said:

Agh.  I didn’t realize the 140 vs 120 thing was on this thread.  Derp.  120s will have more total static pressure than 140s.  The bigger the fan area the worse static pressure. In theory at least.  3 120mm high static pressure might yet do it.  Maybe the 140 will be enough.

Yep, I heard this theory as well. I think everything lies in the fanblade design. Number of the blades and the spacing between them. Oh and also the blade angle, and motor torque. Some motors spin slower, but have a higher torque, some spin faster, have smaller torque. Even the bearings are have to be different, because of the the blade assembly puts more linear stress on the bearings in case of a higher blade angle, or at more pressure. It's like a balancing act. 

And you can bulid the best, most silent motor into a fan, but the sound of the air moving through will have a huuge effect on the sound signature of the device. 

[Bombastinator]

2 minutes ago, Laz_ said:

Yep, I heard this theory as well. I think everything lies in the fanblade design. Number of the blades and the spacing between them. Oh and also the blade angle, and motor torque. Some motors spin slower, but have a higher torque, some spin faster, have smaller torque. Even the bearings are have to be different, because of the the blade assembly puts more linear stress on the bearings in case of a higher blade angle, or at more pressure. It's like a balancing act. 

Not everything. Physics is still physics, though fan angle is physics too.  And it is details.  The question is can you do those angle and other detail games on a 120 as well as a 140?  It’s the  numbers in the end that matter.  There should be CFMs and static pressure numbers somewhere.