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Question Case fan placement - bottom or top?

rh71

No Lifer
Aug 28, 2001
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649
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Have 3 desktops and ordered 3 additional case fans. They each already have the rear exhausting fan, 1 has a front fan. So what's the ideal placement for the 1 extra fan - bottom blowing up, or top blowing out?

And what's the deal with those cases where the bottom section housing the PSU is cut off entirely from the rest of the case? I suppose it would depend on the front fan then?

At what point of "too hot" does it really affect a CPU/GPU in terms of lower gaming FPS? I'm thinking it really won't and has more to do with longevity of the hardware?
 

Stuka87

Diamond Member
Dec 10, 2010
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Well, the answer to your question really depends on the case in use. The specific case can in many ways dictate if intake or exhaust is better. Plenty of arguments for positive pressure, negative pressure, or neutral fan setups.

Without knowing any details, an exhaust fan above the CPU area will help pull heat out of a hot zone if you are using a conventional heat sink and fan setup. The bottom intake will do more to help the GPU, but can also pull dust/pet hair off the surface that the computer case is sitting on.

As for what is "too hot", obviously if the temps are high enough that they result in the CPU/GPU throttling, than you have an issue. In terms of hardware longevity, this mostly only impacts parts that are heat sensitive over time, such as electrolytic caps.
 

rh71

No Lifer
Aug 28, 2001
52,434
649
126
Honestly, I only had the idea to buy more fans because my personal PC's GTX 1060 GPU fan spins up much louder when I play a particular game (Division 2). I was hoping by adding a case fan (or two) that it'd still be quieter than a GPU fan going hyperdrive. This case has the front fan - maybe bottom would be better than top for this machine. GPU temp reads 83C max after the game... is that beyond normal? I know max threshold is maybe 100C. Idle is around 40C.

And this is probably the last time I buy a GPU with only a single fan.
 
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UsandThem

Elite Member
Super Moderator
May 4, 2000
13,074
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In just about all "optimized fan" case review I've seen, having extra fans placed at the front of the case results in lower GPU and CPU temps.

Of course there are always the random case that is so choked off in the front, that adding another fan there that doesn't make much difference.
 

Stuka87

Diamond Member
Dec 10, 2010
4,837
541
126
Honestly, I only had the idea to buy more fans because my personal PC's GTX 1060 GPU fan spins up much louder when I play a particular game (Division 2). I was hoping by adding a case fan (or two) that it'd still be quieter than a GPU fan going hyperdrive. This case has the front fan - maybe bottom would be better than top for this machine. GPU temp reads 83C max after the game... is that beyond normal? I know max threshold is maybe 100C. Idle is around 40C.

And this is probably the last time I buy a GPU with only a single fan.
83C is on the higher side, but not abnormal or dangerous.

The GPU will cause case temps to go up (assuming it is an open frame cooler and not a blower). So getting cooler air in for it should help keep the GPU fans from having to spin as fast.
 

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