Quick question for anyone with Coolermaster 840

Flanno · 24 Nov 2009 at 16:15

Has anyone with an 840 added 2x120mm fans to the outside of the HD bays and did it help GPU temps ?

I've read a few reviews of the 840, and 2 things reviewers have consistently commented on is the negative airflow (1x230mm intake, 2x230mm outtakes) not being optimal for sli setups, and cooling not getting to all components on the motherboard due to the 230mm top outake nearest to the HD cage sucking fresh air out (from the bottom from 230mm intake) prematurely before it's got a chance to circulate. Other reviews have mentioned the sheer distance between the single 230mm intake makes direct gpu cooling difficult.

Where I am coming from is I am thinking of changing to this 840 all the same as I like the look of it. Would the following address the issues some reviewers have found and turn this into a positive airflow case :

1. Add 2x120mm Scythe Gentle Typhoon 1450rpm fans to the outside of the front HD cages to help cool GPU's more directly, and possibly a 3rd to the bottom intake. I wonder would these intakes on the HD cages possibly cause turbulence given their proximity to the front 230mm intake ? I'd probably use a fan controller to drop the speeds when not gaming. The stock front intake would run off the motherboard case fan header.

2. Reverse Corsair H50 (currently outtake with 2 apaches in push/pull using PWM) so it intakes.

3. Use gpu duct (with another Scythe Gentle Typhooon) so it exhaust the hot air from the gpu sideways, so it doesn't get sucked back in by H50.

4. Outake would still be handled by top 230mm fans. And both running off motherboard case fan headers.

Flanno · 24 Nov 2009 at 20:00

Somone with an 840 must know the answer

Flanno · 25 Nov 2009 at 20:37

EsaT, would you be so kind as to comment on my questions above please ?

EsaT · 25 Nov 2009 at 21:32

Adding 120mm fans to HDD cage would surely help some (at least components without own cooling system) by refocusing airflow and would also increase intake airflow from front because lower pressure generated by those two fans lowers impedance of HDD cage like it shows to front intake fan. (just like it's easier to drive bicycle to downwind)

There should be well enough exhaust power for using rear fan as intake and it would be also easy to add dust filter in there if necessary. (that just doesn't make overall airflow any clearer)
Another thing to try would be using frontmost top fan as intake, as default it isn't exactly beneficial for maintaining airflow over hot components so why not to check could it be used more effectively.

Although 5870 exhausts most of its heat having additional exhaust airflow out from expansion card area would be always good thing with multiple cards so using that "external exhaustion chamber" would be worth of trying. Again its effect would be biggest to cards without own cooling system.
(also Lian Li BS-03/06 would be probably possible to mount if that "wart" doesn't look good)

Flanno · 25 Nov 2009 at 21:43

Cheers mate. I agree with all your suggestions there, and thought of changing the frontmost top fan to an intake too

A couple of people have reported having the H50 intake as Corsair recommend can sometime pull in hot air expelled from the video cards. That's why I was thinking the duct would be useful as it's designed to push hot air from the cards sideways according to Coolermaster, so it doesn't get pulled back in. Sounds like a plan. Probably will go for the 1250rpm Gentle Typhoons though. Should be quiet enough at 12v.