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Question Removing hot air around GPU with centrifugal fan

CU

Platinum Member
Aug 14, 2000
2,296
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Does anyone know of any articles or videos of someone testing a centrifugal fan mounted to the mesh next to the pci-express slots on some cases like the Meshify C or Lian Li Lancool II Mesh. It would seem like using one there as an exhaust fan would bring down GPU temps by removing the hot air around the GPU.
 
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BonzaiDuck

Lifer
Jun 30, 2004
14,886
1,023
126
Does anyone know of any articles or videos of someone testing a centrifugal fan mounted to the mesh next to the pci-express slots on some cases like the Meshify C or Lian Li Lancool II Mesh. It would seem like using one there as an exhaust fan would bring down GPU temps by removing the hot air around the GPU.
Do you mean a BARREL FAN, like a smaller version of the CoolerMaster Cross-Flow (13" long!!).

You might want also to look at "slim" (half-inch-thick) 92mm fans.

My approach would be different. My current strategy just needs a bit of refinement. Orient a cross-flow fan so that it exhausts through the forward motherboard pan to the ventilated case-right-side-panel, drawing air from between a Lexan duct panel above the mobo as well as from below the mobo. And extend it with a duct-box drawing from the rear-side of a "mini-OC" graphics card.

Alternatively, you might be able to just build a single duct-box allowing airflow exhaust behind the graphics card, perhaps sticking a 40mm "pusher" fan with the exhaust going out the PCIE slot between the GFX and the CPU cooler.

I'm sure there are all sorts of ways to do it. Most folks here who worry about their GFX temperatures and who use full-size GFX cards recommend water-cooling. But you can make improvements for air-cooling, some to involve the tedium of cutting and gluing 1/8" Lexan plate. Foam-art-board is easier, but neither pretty nor offering visibility for your components.
 

CU

Platinum Member
Aug 14, 2000
2,296
20
81
Something like this fan. It would be mounted to blow out the back of the case through the mesh I was talking about. Could probably mount one above the gpu and blow out the slot right above the gpu depending on the size of the fan chosen.

No plans to water cool. I just ran across some posts that showed people testing 40mm - 90mm fans below the gpus. They cooled better as exhaust fans than intake fans. Theory being that it was removing the hot air around the gpu pulling fresh cool air from the front intakes toward the gpu. I am sure it varies what works better from case to case and fan setup, but was interesting.

Reason I started thinking about this was my rx570 is undervolted and overclocked and stays around 78 while gaming. The XFX backplate doesn't use thermal pads or anything to draw heat, but it is pretty warm to the touch. Also removing the side panel didn't seem to change the temperature more than 1 degree. So, I was thinking maybe hot air was just seating near the gpu. Or, that is all the factory heatsink can do. I also thought about removing the stock shroud / fans, and putting a pair of 120mm fans on it. Probably cool better and be quieter. I have seen that done with good results. Could try a pusher 120mm fan at the end of the card to help push the air from the front of the case across the front and back of the card. I haven't seen that done, but it might help some with larger cases where the front fans are farther away from the gpu.
 

BonzaiDuck

Lifer
Jun 30, 2004
14,886
1,023
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[2]Something like this fan. It would be mounted to blow out the back of the case through the mesh I was talking about. Could probably mount one above the gpu and blow out the slot right above the gpu depending on the size of the fan chosen.

No plans to water cool. I just ran across some posts that showed people testing 40mm - 90mm fans below the gpus. They cooled better as exhaust fans than intake fans. Theory being that it was removing the hot air around the gpu pulling fresh cool air from the front intakes toward the gpu. I am sure it varies what works better from case to case and fan setup, but was interesting.

Reason I started thinking about this was my rx570 is undervolted and overclocked and stays around 78 while gaming. The XFX backplate doesn't use thermal pads or anything to draw heat, but it is pretty warm to the touch. Also removing the side panel didn't seem to change the temperature more than 1 degree. So, I was thinking maybe hot air was just seating near the gpu. Or, that is all the factory heatsink can do. I also thought about removing the stock shroud / fans, and putting a pair of 120mm fans on it. Probably cool better and be quieter. I have seen that done with good results. [1]Could try a pusher 120mm fan at the end of the card to help push the air from the front of the case across the front and back of the card. I haven't seen that done, but it might help some with larger cases where the front fans are farther away from the gpu.
[1] Yes -- I have a Rube-Goldberg imagination, but I never try everything I concoct in my mind. But that solution would seem quite feasible. Just remember that you begin to crowd up your case with extra parts . . .

[2] Glad you posted that link. I've seen plenty of those, and at one time had a thought about using one. They're fairly common. Very much like some fans built into graphics cards. How noisy? I couldn't say. Maybe worth trying.

Another thought which you can at least file away in an inventory of ideas: If you could use Grizzly Conduct-o-naut for the TIM between CPU-IHS and heatpipe-cooler base, you could also use it for the graphics card. On the other hand, graphics cards often have heatsinks on the RAM chips in addition to the heatpipe cooler for the main graphics chip, and the deployment is often an integrated design. One would have to dis-assemble the graphics card just to see, unless someone else has provided photos and an example online somewhere. You might look for it online; I'd bet its documented here or there.

But the TIM replacement is a lot of tedium, and with Thermal Grizzly, you' d need to be very careful, since it is electrically conductive.

I personally gave up fretting over graphics cards. My last SLI configuration used two MSI nVidia 970 cards. For what I do and even my gaming, I don't really need two cards. My most recent card is a Gigabyte GTX-1070 Mini-OC. It's shorter than 7" with a single fan, overclocks well enough, and I don't worry that much about the temperatures.

With Kepler and beyond, what does anyone really need? The only problem: you can't even find a mainstream second-tier card for a reasonable price right now. the word on the street suggests a supply logjam and people buying them to do bit-coin mining.

Truth is -- I NEED one this year, but I can't find any at the moment. Even my GTX1070 is currently priced at what I paid for it four years ago.

Go figure . . .
 

chrisjames61

Senior member
Dec 31, 2013
721
443
136
Something like this fan. It would be mounted to blow out the back of the case through the mesh I was talking about. Could probably mount one above the gpu and blow out the slot right above the gpu depending on the size of the fan chosen.

No plans to water cool. I just ran across some posts that showed people testing 40mm - 90mm fans below the gpus. They cooled better as exhaust fans than intake fans. Theory being that it was removing the hot air around the gpu pulling fresh cool air from the front intakes toward the gpu. I am sure it varies what works better from case to case and fan setup, but was interesting.

Reason I started thinking about this was my rx570 is undervolted and overclocked and stays around 78 while gaming. The XFX backplate doesn't use thermal pads or anything to draw heat, but it is pretty warm to the touch. Also removing the side panel didn't seem to change the temperature more than 1 degree. So, I was thinking maybe hot air was just seating near the gpu. Or, that is all the factory heatsink can do. I also thought about removing the stock shroud / fans, and putting a pair of 120mm fans on it. Probably cool better and be quieter. I have seen that done with good results. Could try a pusher 120mm fan at the end of the card to help push the air from the front of the case across the front and back of the card. I haven't seen that done, but it might help some with larger cases where the front fans are farther away from the gpu.
That fan centrifugal fan is a "blower". Nidec makes the best. They move a ton of air but operate at high rpm's and are loud.
 

CU

Platinum Member
Aug 14, 2000
2,296
20
81
Know of any good pwm blower fans? I would want to control it to control the sound.
 

CU

Platinum Member
Aug 14, 2000
2,296
20
81
Did some testing to find out if I could cool my GPU down any more by adding a fan somewhere. Turns out not really. I ran FurMark and the temp was 83. With the side panel off it was around 81. If I take control of my case fans and run them full speed I can drop it down to 82 with the side panel on. I used an old 1100rpm 120mm fan and put it blowing from front to back in front of the gpu, under the gpu blowing up, beside the gpu blowing toward it, exhausting out the back around the gpu, and as an intake pulling air in from the back of the case around the gpu. All that was done with the side panel on. And, none of it made a difference. Seems the heatsink on it is doing all it can. Only other thing I might could do would be to remove the heatsink, repaste it, and run better 120mm fans instead of the factory ones. Probably not worth the effort though. So, I think I will just let it run. It stays around 77 in games which is fine. On the plus side case air flow seems pretty good as nothing I did really made a difference. Even the side panel off didn't change it that much.
 

BonzaiDuck

Lifer
Jun 30, 2004
14,886
1,023
126
Did some testing to find out if I could cool my GPU down any more by adding a fan somewhere. Turns out not really. I ran FurMark and the temp was 83. With the side panel off it was around 81. If I take control of my case fans and run them full speed I can drop it down to 82 with the side panel on. I used an old 1100rpm 120mm fan and put it blowing from front to back in front of the gpu, under the gpu blowing up, beside the gpu blowing toward it, exhausting out the back around the gpu, and as an intake pulling air in from the back of the case around the gpu. All that was done with the side panel on. And, none of it made a difference. Seems the heatsink on it is doing all it can. Only other thing I might could do would be to remove the heatsink, repaste it, and run better 120mm fans instead of the factory ones. Probably not worth the effort though. So, I think I will just let it run. It stays around 77 in games which is fine. On the plus side case air flow seems pretty good as nothing I did really made a difference. Even the side panel off didn't change it that much.
You have a good point, that there's no sense for the additional air-flow effort if some thoughtful testing proves it less effective.

The only other thing I can think of that might help more noticeably would be replacement of the TIM between the heatpipe base and the graphics processor die, maybe with something like Grizzly Conduct-o-naut. But then, you may have to extend your efforts to the graphics card memory chips.

This effort can be tedious, and even risky. I would think it through as one might explore the dis-assembly first without actually doing it.
 

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