6990 temperature 100

[Maxxx]

You needa get one of those PCI express extender cables + get air blowing on the cards. Mine are in a closed case with a fan blowing air onto the top of the cards, and one blowing air from inside the case towards the back of the case across the cards. There is a few inches between them, and they top out at 90 Celsius for a few hours on a hot day, core clock OC'd to 940. Each GPU is generally 70 to 75.

I also have some of those PCI slot coolers that suck air and blow it out of the case spaced under each card. The amount of HOT air blowing out of the back of this case is like 10 blow driers. I try to keep it pointed out the sliding glass door when I'm home. I'll have a good heater when winter comes along again though. It sucks 11 amps from the wall socket in full operation too.

Edit:

This is the PCI slot cooler I'm talking about.
http://amzn.to/jcJdZS

[licutis]

You needa get one of those PCI express extender cables + get air blowing on the cards. Mine are in a closed case with a fan blowing air onto the top of the cards, and one blowing air from inside the case towards the back of the case across the cards. There is a few inches between them, and they top out at 90 Celsius for a few hours on a hot day, core clock OC'd to 940. Each GPU is generally 70 to 75.

I also have some of those PCI slot coolers that suck air and blow it out of the case spaced under each card. The amount of HOT air blowing out of the back of this case is like 10 blow driers. I try to keep it pointed out the sliding glass door when I'm home. I'll have a good heater when winter comes along again though. It sucks 11 amps from the wall socket in full operation too.

Edit:

This is the PCI slot cooler I'm talking about.
http://amzn.to/jcJdZS

I tryed this fan along with its 2 slot cousin and found them worthless. They just dont move enough air and they block airflow already used by the on board cooler. I did end up removing all the case fans from my dual 6990 miner and placing a normal house box fan facing in on top of it, cooling solved. Hottest core 80 oC in a 84 oF room. I will likely explore all passive cooling of this nature soon.