X79 build: Fractal Design Define XL + Corsair H80 fan directions

[feared]

I've been wondering which way to install the various fans in my system. I've made a custom partition so I can have my Corsair H80 on rear-intake in push/pull, i.e. a third zone for CPU and RAM.

I'm thinking about which way I should point the intake fan in the picture

On the one hand, having it as an intake will give positive pressure and force all the air out of the top 180mm fan. On the other hand, maybe it's better to disconnect the 180mm and have all the air going straight out the front but then it might mix with the lower intakes.


I've got the following hardware:

Asus Sabretooth X79
i7 3930k
8x4gb Corsair Dominator
2x Sapphire 7970 3gb 925mhz
OCZ 240gb SSD
1tb Velociraptor
2x2tb WD Green

The case is a Fractal Design XL

 

[Roady]

Came across this when looking for pics of Fractal builds!

I'd say depending on your heat generated and what you're using your drive bays for will depend on the airflow... Also how 'enclosed' the case is.

If the case is quite enclosed (close to wall, desk surrounding while on the floor etc) then the rear intake is going to draw heat back in that's been exhausted by the 7970's and PSU.

If you are using the middle HDD bay then it's going to block a lot of air coming in, you may then find the 7970's pulling air through your partition and H80 area making a bit of a heat 'circle' with older warm air just circulating...

If you have some good intake in the middle/top front (DVDRW in there?) you would have most of your air going front -> back and avoid any old warm air being pulled back in, except at the H80 and even then most will be exhausted out the top! I imagine the top 180mm is good for airflow at whatever speed!

How have you found the case? I'm considering an R4 for my next build...

 

[doyll]

My thoughts:
Define XL is not good design for 2x 7970 GPUs. Getting enough cool air to GPUs and exhausting to from case is the issue. Custom partition is good idea but again, airflow for GPUs is the issue. Are they reference cards with single blower fan or do they have 2x fans on each? Remove HDD cage from in front of GPUs will help.. as will higher H2O/CFU intake fans to supply enough air. We need more intake air than the GPU fans can use (& CPU is it's exhaust), otherwise they eat their on heated exhaust.

Would it be possible to mount H80 in front bays drawing air in? Than use top 180mm and back 140mm exhaust with 3x 140mm front intakes.. That's still only 1x 140mm intake to supply GPUs.

Probably H80 as back exhaust, 180mm exhaust (it needs to be same as rear as they vent one above the other), and everything else intake.