Air duct for crossfire

[scorchedbee]

So i have two gigabyte windforce 7970s in crossfire, there is a gap between of 1 slot, i have two 140mm fans blowing in from the side at 5V to help. Temps get to 79/80 under full load

would there be a point, or has anyone made some form of shroud/duct to push the air from the side fans in between the gap in gpus, so the hottest gpu (top one) gets the cold air to the fans. Im thinking this as i know the aftermarket coolers dump the hot air all over the place from the card.

 

[Dicehunter]

Just a theory here so bear with me,

You would need to directly attach the shroud to the fan/s to direct the airflow between the GPU's without air leaking out the sides of the fans and by the time you put the side panel back on the space left between the fans and the GPUs would be minimal not leaving much room for the shroud.

In theory it could work though if the space was large enough, I've seen it done with CPU heatsinks, Different hardware I know but still the same principal.

You could always get a spot cooling fan maybe ?

Antec does one that gets bolted down to your motherboard and plugs into a fan header so you can control the speed, Has a flexible arm and you could direct the airflow from the front intake fan/s to between the GPU's

 

[scorchedbee]

thats an idea, maybe one on top and one at front of gpus, i didnt want it to be too wide as then would push hot air back inbetween the gap. The temps arn't terrible but just wouldnt mind getting then down

sorry for pathetic paint skills but something to push air in the blue area as heat exits at top and sides of gpu

i was even thinking of using pci-e risers to 'mount' the gpus onto the side panel with custom slots cut so each gpu can get cold air direct, however my plan is foiled by not being able to find a stupidly long crossfire cable!

 

[Wraith]

Blowing more air onto those cards is pointless, you want to get rid of heat.. Concentrate on case Air flow.. Side panel fans really aught to be exhausting the heat from the GPUs unless they are reference blower style cards as they flow air properly out the back.

 

[scorchedbee]

maybe i should just settle for the temps i have and transfer my rig to a air 540 or 760t!

probably also explains the the side fans arnt really doing anything, as if i put on 12v, 7v or 5v temps are the same!

 

[Dicehunter]

maybe i should just settle for the temps i have and transfer my rig to a air 540 or 760t!

I can whole heartedly recommend the 540, I have it and the airflow is fantastic but do some research first, The Video reviews section is a good pitstop as there are quite a few really good videos on different cases

 

[Wraith]

79 - 80C at 100% on dual 7970s is pretty good tbf, especially as it's summer time.

 

[Agost]

What are your temp results with those fans @7V, @12V and without them?

However, corsair AFs are not so good... you aren't using an AF for your rad, are you?

How many fans do you have in the case? 5? 6?

 

[scorchedbee]

i have 2xAF140mm at front as intake, 2xAF140mm on side as intake

2xAF120mm on top as exhaust and 1xSP120 on rad as exhaust

all fans running at 5v using a NXZT sentry mix 2 and gpu fans 20% upto max of 50%.

 

[Agost]

Did you try 7V and/or a bit higher gpu fan speeds?

What do you mean with "full load"? Unigine tests/ 3DMark or gaming?

 

[barnsley]

Air ducts don't really work on that design of GPU in my opinion as they jus chuck out heat everywhere. If your cards were reference I could see that working.


Also if you want a case that does cooling very well then I'd say get either a HAF case from coolermaster or even a silverstone RV03. Just don't expect the HAF case to be that quiet...
Corsair stuff looks nice but doesn't always have the best possible thermal performance. My friend's Air 540 rig has similar specs to yours (dual Sapphire tri-x 280x, 3770k,h100i)and it tops about 81-ish with a pretty average fan curve.

 

[JR23]

Blowing more air onto those cards is pointless, you want to get rid of heat.. Concentrate on case Air flow.. Side panel fans really aught to be exhausting the heat from the GPUs unless they are reference blower style cards as they flow air properly out the back.

+1 Set your side fans to exhaust.

Negative case pressure will benefit those areas where it's difficult to get flow through like inbetween graphics cards and it should prevent some of the warm air passing through the CPU cooler. I wouldn't change case about it personally as you will always suffer from the same problem when stacking open design GPU's so tightly. Moving the cards further apart with different motherboard spacing doesn't make much difference, the only thing which reduces the problem is blowers tbh, i've tried a few different setups.

JR

 

[scorchedbee]

ok just put the side fans to exhaust will test now

this is my fan profile, love the silence!

 

[scorchedbee]

so i swapped my top fans as intake, then only the h60 sp120 fan and the 2xaf140 on side are exhausts. Again all fans set to 5v and GPU using same profile as above

these are my max and min temps, ran prime95 for and hour with furmark running, then played BF4 for over an hour, temps are pretty good i feel!

 

[iBeInspire]

Swap your side fans to exhausts. The cards dump hot air out of the side of the cooler, all your side fans are doing is pushing that hot air back into the cards. You then need your roof fans as exhaust also, since heat rises... if your top fans are intaking then again all they are doing is pushing hot air that wants to get out, back in. This will likely mean a negative pressure in the case, so if you can I would bump the front fans to the next voltage up (5v -> 7v, 7v -> 12v) or if you're a silence freak, just clean the case a little more often.

Realistically, this is pretty much going to be the best you can do without watercooling or doing something custom, and to be honest your temps are decent, you shouldn't really need to do more than what I've mentioned

 

[Wraith]

Averaging 8c lower GPU temps much better it's the one problem with non reference graphics cards, they do a p!ss poor job of dissipating heat correctly rather than the obvious, get it out the case they just dump it anywhere.

EDIT: Since you switched to side exhaust fans your temps actually mirror mine at full load & idle.

 

[Excalabur50]

I had similar issues with my 7970's and I changed to a Switch 810 and I have 2x140mm pulling in from the front then just behind the HDD cages are 2x140mm fans angled to blow air at the cards the rear 140 pulls air in and the two 120mm on the H100i vent air out the top and I get really good temps at Idle my Gpu's are around 45 Deg C and under load about 75 Deg C