How do you cool 4 Cards, all bouble slot?

[Fuzzy]

I have a machine with 4x 6950s and the heat cascades from the bottom card (~75'C) all the way to the top card (~100'C), as each card sucks air off the back of the card below it, which pre-heats the intake air, and makes cooling the core less efficient, so the core is always a higher temp than the card below it.

Are there any tips or tricks to cooling cards that are sandwiched together?

I've already inserted rubber grommets between them for an extra few mm of spacing, and removed the metal face plates off of the input connectors to improve exhaust capacity.

Anything else I can do?

[nodemaster]

I use watercooling with my 5870 "sandwich". Core Temp was like yours with standard fan cooling. With watercooling the core temp is between 48 and 52 centigrades from bottom to top of the sandwich.

[fascistmuffin]

Are you running the cards in a case? Have you tried adding a side fan if possible?

[Fuzzy]

I wish I could justify the extra cost of water cooling, but with with the difficulty making mining that much harder, and the crash in value, there's just no way I can spend $80 per block per card, plus pump and rads.

I'm looking for solutions that need no more than duct tape and WD-40...

Are you running the cards in a case? Have you tried adding a side fan if possible?

I have 4x 120mm fans at the front of the case (the old CM Stacker) and the centrifugal fan blowing across the motherboard.

I will try adding an 80mm fan aimed at the top two cards, but I'm guessing the cross wind will just carry that flow straight out the back exhaust.

[harm]

How much did you pay for the water colling system? Is it realy worth it?

[nodemaster]

As you asked for a quick and dirty solution: have you tried putting two 120mm fans onto the sandwich? They should blow between the cards in order to support the cards fans.

Edit: I see you already did...

[grue]

long time ago there was asbestos liquid spray if you can get something similar just spray on the back of your GPU  if you dont have any other alternative just put a piece of glass make sure the fans dont touch the glass

that only insulates each card from each other. the heat produced and dispersed is still the same, so that doesn't fix the problem at all

[RyNinDaCleM]

You can wedge something small (1-1.5cm thick) between them, to hold them apart, then as others said, mount 2 120s to the sandwich!

[grue]

long time ago there was asbestos liquid spray if you can get something similar just spray on the back of your GPU  if you dont have any other alternative just put a piece of glass make sure the fans dont touch the glass

that only insulates each card from each other. the heat produced and dispersed is still the same, so that doesn't fix the problem at all

yes but that is the problem because the card alone never go above 80ºc and after you do that you can add a home made "wind tunnel" for the gpu's (if you dont have a case) so you get a one way air flow and a decent speed

lol, your house will be full of asbestos if you do that.

You can wedge something small (1-1.5cm thick) between them, to hold them apart, then as others said, mount 2 120s to the sandwich!

that will stress the PCB/PCIe connectors

[CydeWeys]

Yank that mobo out of the case, build a two-tier chassis out of angle aluminum or wood, and take two of the cards off the mobo and put them on adapter riser cables.  That'll free up a lot more space between cards and give you a lot more room to run fans.  If you already have a bunch of spare wood laying around like I did then you're only out the cost of the cables, which ran ~$30 in my case.

[Jack of Diamonds]

long time ago there was asbestos liquid spray if you can get something similar just spray on the back of your GPU  if you dont have any other alternative just put a piece of glass make sure the fans dont touch the glass

that only insulates each card from each other. the heat produced and dispersed is still the same, so that doesn't fix the problem at all

yes but that is the problem because the card alone never go above 80ºc and after you do that you can add a home made "wind tunnel" for the gpu's (if you dont have a case) so you get a one way air flow and a decent speed

Asbestos has been illegal for over 30 years in most countries, google it.

If you go into a room with asbestos (let alone spray some in your near vicinity) you are increasing your risk of fatal cancer by a factor of about 100,000. Not really a good idea.

[CydeWeys]

No, Jack, don't discourage asbestos use.  If other miners get mesothelioma then that leaves more blocks for me.

(Kind of ironic here how we're bringing in the risks of real-world mining to virtual mining.)

[DarkKnightNomeD]

Here you go! LOL


http://www.newegg.com/Product/Product.aspx?Item=N82E16835706015


---------------------------------------------------


Bearing Type:
    Ball Bearings

RPM:
    5500 RPM

Air Flow:
    252.85 CFM

Noise Level:
    66.5 dBA

Power Connector:
    3 bare wire or 4-pin Rated Voltage : 12V Operating Voltage Range : 8 ~ 13.2V Rated Current: 4.80 amp Rated Input Power: 48W Air Pressure: 35.877 mm H²O

Color:
    Black

Compatibility:
    Case

Dimensions:
    120 x 120 x 38mm

[CanaryInTheMine]

And just let this sucker blow on the cards?

If the case is going to be closed (with this fan as a side intake), you'd need to improve outflow as well somewhere else in the case...

[grue]

And just let this sucker blow on the cards?

If the case is going to be closed (with this fan as a side intake), you'd need to improve outflow as well somewhere else in the case...

MOAR FANS. or open the case, and point a big fan into it.

[hennessy]

Using two 12cm Fans, both lying right on top of the cards, blowing air into the gaps. I'm getting 56 - 74°C, all cards OC'ed from 800 to 950Mhz.

[PulsedMedia]

I had a similar problem with 4 5850's in a case,

I bought 2 PCIe extenders (kinda pricey @ $25 each, but you got to take care of your tools as my father would say.)

and built a aluminum bracket and my temps are now way cool.   from 88ºC down to 60ºC.
pics here:

that looks insane, more pics please!

[malevolent]

Here you go! LOL
http://www.newegg.com/Product/Product.aspx?Item=N82E16835706015
---------------------------------------------------
Bearing Type:
    Ball Bearings
RPM:
    5500 RPM
Air Flow:
    252.85 CFM
Noise Level:
    66.5 dBA
Dimensions:
    120 x 120 x 38mm

66.5 dBa?! You have any idea how much noise is it going to generate???

[PulsedMedia]

Here you go! LOL
http://www.newegg.com/Product/Product.aspx?Item=N82E16835706015
---------------------------------------------------
Bearing Type:
    Ball Bearings
RPM:
    5500 RPM
Air Flow:
    252.85 CFM
Noise Level:
    66.5 dBA
Dimensions:
    120 x 120 x 38mm

66.5 dBa?! You have any idea how much noise is it going to generate???

Atleast i do, Yes, 66.5 dBa

In all seriousness tho:
http://www.gcaudio.com/resources/howtos/loudness.html
That is about as much as normal conversation.

Currently at my workstation the noise level is probably plenty above 66.5.

[computerparts]

I had a similar problem with 4 5850's in a case,

I bought 2 PCIe extenders (kinda pricey @ $25 each, but you got to take care of your tools as my father would say.)

and built a aluminum bracket and my temps are now way cool.   from 88ºC down to 60ºC.
pics here:

That wiring job just screams fire hazard.