Side panel fan as intake or exhaust?

[rakibfahadgts]

I've 4 fans in my casing (2 front, 1side panel, 1 at the back). Front ones are intake and the rear one is an exhaust. Thing is I'm not sure whether to use the side panel one as intake or exhaust. So far I've tried both (intake=positive air pressure, exhaust=Neutral air pressure). Can anyone please explain which one's best for CPU and which is best for GPU. I've heard there's a trade of between CPU and GPU temps in both scenario as the fan sits right below the GPU.

In addition I don't have designated space for mounting fans at the case ceiling so I'm stuck with 2 fronts, one side and one rear. I am aware of the consequences of dust build up when using the fan as an exhaust but I want to know which one's better for cooling only.

TIA

 

[Rdslw]

I've 4 fans in my casing (2 front, 1side panel, 1 at the back). Front ones are intake and the rear one is an exhaust. Thing is I'm not sure whether to use the side panel one as intake or exhaust. So far I've tried both (intake=positive air pressure, exhaust=Neutral air pressure). Can anyone please explain which one's best for CPU and which is best for GPU. I've heard there's a trade of between CPU and GPU temps in both scenario as the fan sits right below the GPU.

In addition I don't have designated space for mounting fans at the case ceiling so I'm stuck with 2 fronts, one side and one rear. I am aware of the consequences of dust build up when using the fan as an exhaust but I want to know which one's better for cooling only.

TIA

side panel is near CPU so if you mount it as exhaust it will take air from same "pool" as CPU cooler. it usually means CPU will have less HOT air around.
if you mount it as intake, again you blow nice cold air into CPU, but then exhaust around top/back push out this air instead of front panel air. it means cool air from front panel does not go though whole case, cooling gpu and other parts in the process.

i would say mounting it as exhaust would result in:
gpu temp-
cpu temp-
and intake:
cpu temp--
gpu temp+

this can also be regulated with strength of each fan. check and make sure its slightly positive air pressure to keep dust out.

 

[photonboy]

1) Hard to say as it depends a lot on the hardware you have

2) for example, if the CPU cooler is a basic heatsink + fan, with the fan blowing towards the REAR of the case it's likely to have MINIMAL impact either way as the fan is still pushing air through the heatsink fans with enough pressure that is very hard to steal; but any differences would be multiplied if the CPU cooler is relatively weak.

(technically the top/rear fan can bypass the CPU heatsink by wasting pressure sucking in air from the top/top slot if its left open but my experimenting didn't show much difference if I BLOCKED the top fan slot... not sure if the pressure difference doesn't matter much or whether the passive heat exhaust compensates for any losses... see how complicated it gets?)

3) generally speaking side fans best serve the graphics card, and more specifically the closer the fan to a component the more it matters.

4) I've tested this myself in a few setups and determined that with a good CPU cooler, 1x exhaust and 2x intake fans a side fan (AS INTAKE) had little affect on the CPU but if your graphics card is prone to throttle it may help performance a bit, or at least reduce the NOISE level slightly

So...
Long story short I'd first look at which part has the weaker cooler in terms of throttling. The CPU or the Graphics Card?

You also want to optimize the FAN SPEED for every fan or you defeat the purpose of adding another fan. There is an optimal balance of noise vs cooling and frankly if you are having a hard time figuring out how much the side fan matters then it likely doesn't matter much at all.

 

[photonboy]

Also make sure the side fan won't hit your CPU cooler, and if you do get one I'd considering setting to a low, non-variable RPM. A good fan should have little to no noise at around 500RPM.

The Noctua NF-S12A (12cm) is possibly the best side fan if you don't care about color. It can be controlled down to roughly 300RPM with the LNA (low noise adapter that comes with it) so it's essentially silent at probably up to 500RPM or so, and frankly I doubt there'd be much difference to graphics cooling trying to intake more air as there's rapidly diminishing returns.

I would probably set a flat profile in the fan software to 500RPM and not bother tying it to a specific temperature sensor.