Build Advice RTX 3080 Theorycraft Air Flow

SentrySteve

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Hello everyone,

When it comes to building a PC my knowledge is basic and fundamental. I hadn't done it in a decade, but I recently built a new PC that included a Ryzen 9, x570 board, and a meshify C case. The only thing I didn't purchase was a new GPU; I am using a GTX 1060. I'm sure like many of you, I'm very interested in the new RTX 30 series; specifically the RTX 3080. If I'm able to pull it off, I'm considering buying the founders edition with has a fan design in which hot air is expelled directly in-front of the CPU. While I don't have it yet, I was also considering purchasing the Noctua NH-U12A CPU fan (currently using the included AMD Wraith Prism fan)

My concern is that the 3080 Founders will expel hot air which will then be picked up by CPU fan, raising the CPU temp. Given that I don't know much about building PCs, and I know even less about air flow, I did some research and found all sorts of fun and confusing information out there. My major (generally accepted as true) take aways are: air should enter through the front and be expelled out the back/top. That said, sometimes air flow doesn't do what you think it should.

For fun, I decided to theorycraft how airflow could work in my case with a noctua fan and a founders 3080. I'm looking for feedback on my second suggested build to see if it's a good idea.

Picture 1 is what I perceive to be the traditional airflow, blue boxes represent intake fans, red represent exhaust, with orange showing the potential hot/cold mixed air impacting CPU cooling. Black boxes represent empty fan placements. I imagine those who purchase a 3080 and don't have liquid cooling will have a build similar to this.

Picture 2 involves rotating the direction of the CPU fan (I assume this is possible?), changing the back exhaust port to be an intake (adding an after market filter), then using the top front fan to exhaust the air out of the system. An option would be to include another fan, at the topmost front position, to also exhaust air -- but that fan would be next to an intake, which I can't imagine is a good idea but I haven't a clue. The perceived advantage here is all hot air pushed to one area (top front) while CPU would receive fresh and likely more cool air than build 1 (although there is still an exhaust relatively close, at least it's not literally pumping hot air into the CPU fan)

I'm looking for feedback from my experienced users; I don't intend on overclocking anything but I'd like to keep my temps down to ensure my components enjoy a long life. Am I over thinking this? Is it too early to actually tell and this is all a bit pointless? Or could the second mock up represent a potentially workable solution?


 
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Phaaze88

Glorious
Ambassador
Nothing has changed.
Nvidia's FE design for the 30 series is doing what AIB axial fan cooled models have been doing for years now: dumping gpu exhaust into the chassis, some of which gets pulled into the cpu air coolers and hybrid coolers(depending on placement).

Heck, the 3080 and 3090 MIGHT even be more efficient than what the AIB axial fan models do, which is dump their heat in the chassis across the length of the gpu.
This new design appears to dump heat into the chassis across half the card - if that - and the other half dumps it out the back.

Either way, some people are overreacting to this.
 

SentrySteve

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Nothing has changed.
Heck, the 3080 and 3090 MIGHT even be more efficient than what the AIB axial fan models do...
This new design appears to dump heat into the chassis across half the card - if that - and the other half dumps it out the back.
That's a really good point, one I hadn't considered.


I would go with #1 but move the bottom fan to the front. No reason to overthink it.

Buying the aftermarket cooler is a big yes.
Thank you!
 

hotaru.hino

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What I don't get is people think current cooler designs, where it's just two-three axial fans blowing over a heatsink onto PCB (a wall) with the air being pushed out towards the motherboard (another wall) and the side panel (yet another wall) is better than a design where the air being sucked up to cool the heat sink has a more or less clear path to where air is supposed to be flowing out of the case. The design makes it so air efficiently moves through the case, rather than stir around and hope the case fans can replace the air in a timely fashion.

If this is enough to cause CPUs and RAM to overheat, then that sounds like it's more of a problem with not getting enough air circulating around that part of the case.
 

DSzymborski

Polypheme
Moderator
Better to overthink than underthink! In this case, the temperature gradient between the heat coming off the GPU and mixed with the cool air coming in isn't going to be enough to make any real difference when being blown across the Noctua heatsink.
 
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SentrySteve

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Jun 15, 2011
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Better to overthink than underthink! In this case, the temperature gradient between the heat coming off the GPU and mixed with the cool air coming in isn't going to be enough to make any real difference when being blown across the Noctua heatsink.
Perfect! I went ahead and ordered the Noctua heatsink; next step is getting lucky enough to snag a FE 3080, which from what I've seen people are speculating a short supply available at launch. I appreciate the help guys!
 
Hello everyone,

When it comes to building a PC my knowledge is basic and fundamental. I hadn't done it in a decade, but I recently built a new PC that included a Ryzen 9, x570 board, and a meshify C case. The only thing I didn't purchase was a new GPU; I am using a GTX 1060. I'm sure like many of you, I'm very interested in the new RTX 30 series; specifically the RTX 3080. If I'm able to pull it off, I'm considering buying the founders edition with has a fan design in which hot air is expelled directly in-front of the CPU. While I don't have it yet, I was also considering purchasing the Noctua NH-U12A CPU fan (currently using the included AMD Wraith Prism fan)

My concern is that the 3080 Founders will expel hot air which will then be picked up by CPU fan, raising the CPU temp. Given that I don't know much about building PCs, and I know even less about air flow, I did some research and found all sorts of fun and confusing information out there. My major (generally accepted as true) take aways are: air should enter through the front and be expelled out the back/top. That said, sometimes air flow doesn't do what you think it should.

For fun, I decided to theorycraft how airflow could work in my case with a noctua fan and a founders 3080. I'm looking for feedback on my second suggested build to see if it's a good idea.

Picture 1 is what I perceive to be the traditional airflow, blue boxes represent intake fans, red represent exhaust, with orange showing the potential hot/cold mixed air impacting CPU cooling. Black boxes represent empty fan placements. I imagine those who purchase a 3080 and don't have liquid cooling will have a build similar to this.

Picture 2 involves rotating the direction of the CPU fan (I assume this is possible?), changing the back exhaust port to be an intake (adding an after market filter), then using the top front fan to exhaust the air out of the system. An option would be to include another fan, at the topmost front position, to also exhaust air -- but that fan would be next to an intake, which I can't imagine is a good idea but I haven't a clue. The perceived advantage here is all hot air pushed to one area (top front) while CPU would receive fresh and likely more cool air than build 1 (although there is still an exhaust relatively close, at least it's not literally pumping hot air into the CPU fan)

I'm looking for feedback from my experienced users; I don't intend on overclocking anything but I'd like to keep my temps down to ensure my components enjoy a long life. Am I over thinking this? Is it too early to actually tell and this is all a bit pointless? Or could the second mock up represent a potentially workable solution?


The blow through does create a bad situation for cpu coolers, especially for high tdp chips like the 10 series and Ryzen 9 series chips.

I would do neither. I would get a 280 or 360 cpu rad up front, use the front as intake and exhaust out the rear and or top with 3 fans out.

Today's cpu boost algorithms are extremely sensitive to temp. 5C can make a significant difference in boost.

If you go front aio, I recommend tubes down at the bottom if possible. It will prolong the life and reduce air bubbles in the loop.
 
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