Cooling dual HD4870X2 with Arctic Cooling Accelero Xtreme - helpless

[destabilizator]

Hello guys,
my problem is following: I'm running dual HD4870X2 cards (Sapphire) and recently I bought two of the Accelero Xtreme coolers and mounted them on my boys, hoping it will finally stop overheating. Well temperatures at GPUs dropped, noise dropped, all win. But when playing some game which equally uses both graphic cards (Call of Juarez - Bound In Blood now), it just burns down rapidly and PC shuts down, last line in the log of Everest program shows 122°C on GPU1 VRM.
I tought maybe one of the cards is bad and heats too much, removed the lower card, worked like charm (GPU1 VRM 71°C), switched the cards, same result. When I plug both, system overheats. My guess is because of the lower card's back just pump heat into fans of upper card which ain't cooled much then.
I'd be really grateful for any suggestions how to cool those mofos, I've applied AS5 under all heatsinks, helped a bit, but in the end it still overheats.

Case Lian-Li Armorsuit PC80, 3x 120mm intake fans, 1x 120mm exhaust at back (+ PSU exhaust), 1x 120mm exhaust on the top.

 

[evongugg]

ATI Radeon HD 4800 Series Fan Hacking Guide Rev. 2.0

http://www.techarp.com/showarticle.aspx?artno=583

 

[evongugg]

Some cable managment could help also:

CABLE MANAGEMENT

Take off the left panel of the case. If it has large holes, you can do cable management.
Typically there will be a hole near the PSU and a hole near the hard drive cage.
Typically you pass the power cables out the PSU hole behind the motherboard wall to the hard drive cage.
You can also hide any unused cables this way.
Not all cases have the holes. You could cut the holes yourself. If you do make sure you file the edges smooth so as not to cut any cables. You void your case warranty by altering it with holes.
When reassembling the left panel, do not put excessive force on it. If there is a cable impeding proper closure, remove it rather than damage it.
Cable management makes a big difference in air flow in the case.

Buy zip ties, zip tie mounts, spiral wrap, Velcro ties.

Run cables against wall (Rear fan wall) or behind cages.

If you make holes, spray with tectyl against rust. Use a grommet or door edge trim (at auto parts stores) to protect the wires that go through.

 

[evongugg]

Graphics card Temperatures:

80-90º is average
115º is threshhold
127º burnout

 

[uncfan_2563]

hmm i would personally try to mod your case in some way or use glue for now to hold a fan at the end of the first 4870x2 to take away the hot air its blowing at the other one.

 

[destabilizator]

Thanks for replies guys.

2evongugg: I've even tried opening the case and aiming huge "desktop" fan at the cards, didn't help. As for cable management, I don't have any unused cables (I can plug cables only I need into PSU and put the rest in the box) in the case and all of them are tied as much as possible, but I'll try to look at it again. As for the fan hack, interesting, but when I'm testing it, I put both cards' fans on 100%.

2uncfan_2563: what do you mean by "end of the first 4870x2"?

 

[uncfan_2563]

like get a fan sucking air directly out of the small gap between the cards.

 

[invisik]

Try one card at a time to see if both cards cool properly.

I agree try to put a fan between the 2 cards.

 

[destabilizator]

Try one card at a time to see if both cards cool properly.

I agree try to put a fan between the 2 cards.

Did that, both works fine. Thing is I can't put anything between the cards, there's like 2mm wide space. I've tried to put a thin layer of insulation there, but didn't change anything.

 

[invisik]

Hmmm.

Are the cards overclocked?
whats the fan speed?

 

[invisik]

Put a few 120mm fans on the bottom of the case so airflow is directly towards the cards.

 

[destabilizator]

No, they are underclocked to 500/500 in Windows and 750/900 when running 3D (default clock). Didn't need to overclock them, got enough power :]

 

[clerick]

Hey my friend had a problem like you with 2x acceleroes and here's what we did:

We bought this pci-e extender:
http://www.ameri-rack.com/ARC1-PELX16-Cxm.htm (get the 11mm 16x version)

pluged it in, ten pluged the gpu into it and lowered it downwards (we cut case) and mounted it. Looked something like this and cured his temp problems.

 

[destabilizator]

Hey my friend had a problem like you with 2x acceleroes and here's what we did:

We bought this pci-e extender:
http://www.ameri-rack.com/ARC1-PELX16-Cxm.htm (get the 11mm 16x version)

pluged it in, ten pluged the gpu into it and lowered it downwards (we cut case) and mounted it. Looked something like this and cured his temp problems.

http://i26.tinypic.com/x1lvls.jpg

What about drops in performance? Afaik PCI express slot is very "vulnerable" to timing.

 

[roofus]

you may see if K|ngp|n is making LN pots for the 4870x2's

 

[clerick]

What about drops in performance? Afaik PCI express slot is very "vulnerable" to timing.

Doesn't seem to be an issue.