Extra fan to feed cold air to graphic card makes huge difference

[RejZoR]

We always assumed intake air from front fans is feed to graphic card in sufficient quantity to help it cool well. But I realized that's not really the case as my RTX 3080 was really loud most of the time.

 

So I checked my pile of fans and found one that fits perfectly right underneath the graphic card so it's actually acting as a physical support and also feeding air right into graphic card's fans. I've set it to run with speed where it's inaudible and my god what a difference it makes. Ever since I put the fan there, the card is trying to boost higher and also runs significantly quieter. Basically to a point I can't hear the graphic card anymore even after hours of gaming.

 

Apparently the case fans in the front (I have 3x140mm) don't push enough cold air actually underneath the graphic card where its fans could "grab" it. Just placing extra fan at the end of graphic card so it gets a guaranteed share of cold air from the intake fans makes a massive difference. Maybe this isn't as relevant for really huge cases, but with my mid tower and fact I also have soundcard underneath it helped tremendously.

 

Anyone else with extra fan lying around willing to test this?

[SupaKomputa]

Yes, it make sense. i've done this before.

It's better if you place it under the gpu.

If the air circulating faster, the gpu fan won't need to ramp up as often.

[PineyCreek]

I imagine it would work almost as well with a high CFM fan in the front intake (in the middle position), allowing for loss from the gap between the fan and the end of the GPU.

 

I used to have a card that almost filled the case I was using at the time length-wise where the end of the GPU was within millimeters of the fan, and it seemed to have great thermals.

[RejZoR]

35 minutes ago, PineyCreek said:

I imagine it would work almost as well with a high CFM fan in the front intake (in the middle position), allowing for loss from the gap between the fan and the end of the GPU.

 

I used to have a card that almost filled the case I was using at the time length-wise where the end of the GPU was within millimeters of the fan, and it seemed to have great thermals.

I don't think it would. You'd just have to run it at stupid speeds and it would still just collide on the graphic card end, create vortexes and prevent new air coming in. Here, both run at very low RPM and the front intake is basically just handing over the air to small one that's actually feeding it directly to graphic card. There is just no way front fan could feed air so far underneath graphic card.

[PineyCreek]

17 minutes ago, RejZoR said:

I don't think it would. You'd just have to run it at stupid speeds and it would still just collide on the graphic card end, create vortexes and prevent new air coming in. Here, both run at very low RPM and the front intake is basically just handing over the air to small one that's actually feeding it directly to graphic card. There is just no way front fan could feed air so far underneath graphic card.

mmm...well, I don't have the real estate to test it, but it makes sense that the closer it is the less likely the air current would be diverted or weakened.  It would also depend on where exactly the middle fan is in position in relation to both the PSU basement and the GPU (in the case of seeing if a high CFM fan in the middle section would make a difference) since breaking the flow up with the PSU basement for example would throw off the flow I would think.

 

Sounds like grounds for a smoke test.  I'm not arguing that a fan closer to the GPU would work better though than other solutions...that's common sense.  I'm still curious however if a higher CFM and RPM fan could do as well...but almost definitely not without significant noise.

[RejZoR]

3 hours ago, PineyCreek said:

mmm...well, I don't have the real estate to test it, but it makes sense that the closer it is the less likely the air current would be diverted or weakened.  It would also depend on where exactly the middle fan is in position in relation to both the PSU basement and the GPU (in the case of seeing if a high CFM fan in the middle section would make a difference) since breaking the flow up with the PSU basement for example would throw off the flow I would think.

 

Sounds like grounds for a smoke test.  I'm not arguing that a fan closer to the GPU would work better though than other solutions...that's common sense.  I'm still curious however if a higher CFM and RPM fan could do as well...but almost definitely not without significant noise.

The noise was my main issue. And frankly, even if I ran intake fans at max, I don't think air was being fed to the graphic card well. It was just very noisy. Here, the "middle" fan makes sure it gets a share of air no matter what, for as long as intake fan delivers any. Unfortunately I don't have any smoke generator to try it out. Would be cool if Steve from GN could check this, I think he once did airflow test with smoke. Hm.

[Mark Kaine]

You dont say!

 

it makes around 5C difference actually ~

[RejZoR]

@Mark Kaine

I don't like the idea of sucking air from bottom. I had PSU that way and even though I have my case raised on a dedicated support, I always had bunch of dust on filter in very short time. Also entire support was covered in dust. Rotated PSU and is now fed by air from within case tunnel and there is much less dust now.

[Guest]

And people wonder why I have loud ass case fans.

That's 150 cfms per fan XD. 

Yes, my PC can hover like a drone..... haha.

https://www.amazon.com/Electronics-AFB1212SHE-120x120x38mm-Cooling-connector/dp/B004Y1HLA8

[Mark Kaine]

I agree this isnt ideal with the PSU in the bottom , but mine is on top!

 

But it still shows theres a benefit from fan(s) under the GPU. And yes i need to clean the dust filter like once every 1-2 weeks, but surprisingly theres not much dust on the fans or the GPU itself  (thanks dustfilter)

 

 

[m9x3mos]

This is why I loved the cases which had a fan in the side panel. My corsair case that my threadripper is in with a 1070 and 1060 has 2 120 mm fans in the side panel and it really makes a difference. 

[PineyCreek]

7 hours ago, m9x3mos said:

This is why I loved the cases which had a fan in the side panel. My corsair case that my threadripper is in with a 1070 and 1060 has 2 120 mm fans in the side panel and it really makes a difference. 

Yeah, the Antec 1200 I have for my old system has an acrylic side panel with a space for a fan right over the GPU area.  I miss that in my current case.