[Revolutionary?] Inverting Case Fans

Sherloc09

Limp Gawd
Joined
Jul 22, 2017
Messages
321
So, looking at completing a new build in 2018, and in anticipation of that had decided to try pushing my old i7 920 up into higher overclocks since it's definitely at the edge of it's useful life. One of the items in the new build I'm piecing together is that the top bracket allows for a 200mm fan to be placed -- Enthoo Pro would be the new case. I like quiet running systems and am planning to outfit the Enthoo Pro with a 200mm Noctua at the top and a 140mm Noctua at the rear, both PWM. Since the CPU is going to be air cooled, decided it may make sense to instead of having the rear and top fans exhausting air, to having them instead intake the cold air directly onto the CPU cooler and exhaust from the front. With the limited distance from the exterior of the case to the CPU cooler from the top and rear this would seem to make sense. Below is the current system data collated on the benefit of this approach when implemented on the i7 920.

System Settings Before
Coolermaster Cosmos
i7 920 @ 3.33 ghz @ 1.23 v
Coolermaster V8 cpu cooler running lowest fan setting

FAN SETUP -- Scythe 120mm fan top exhaust, CM 120mm fan rear exhaust, CM 120mm fan bottom intake
TEMPS -- idle 48, in game ~70, synthetic load 86



System Settings After
Coolermaster Cosmos
i7 920 @ 3.33 ghz @ 1.23 v
Coolermaster V8 cpu cooler running lowest fan setting

FAN SETUP -- CM 120mm fan top intake, CM 120mm fan rear intake
TEMPS -- idle 40, in game ~58, synthetic load 72



System Settings After with Higher Overclock

i7 920 @ 3.80 ghz @ 1.25 v
Coolermaster V8 cpu cooler running lowest fan setting

FAN SETUP -- CM 120mm fan top intake, CM 120mm fan rear intake
TEMPS -- idle 40, in game 61, synthetic load 83



TLDR -- Configure top and rear fans to intake cold air and see a drop in temps of ~15 C at same clocks, drop in temps of 3C with overclock of 467mhz + .02v.
 
Last edited:

rgMekanic

[H]ard|News
Joined
May 13, 2013
Messages
4,673
Slightly positive air pressure in the case is always advised for good temps, as well as preventing dust from getting sucked in from between the cracks and gaps in the case.

I my 900D I have 6 120mm fans on intake duty, then 4 120mm and 1 140mm on exhaust
 
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