Hd 6970 and hd 6990 in crossfire

[gert247]

Is it possible to do it?

 

[17seconds]

Yes.
http://www.hardocp.com/article/2011/05/03/nvidia_3way_sli_amd_trifire_redux/

 

[gert247]

Thanx matto<but do I need extra cooling and power? i've got a cooler master 1000w psu.

 

[17seconds]

Thanx matto<but do I need extra cooling and power? i've got a cooler master 1000w psu.

Do you have either card already? The 6990 by itself can get pretty noisy, with a 6970 added, it will be very, very noisy and very hot, to the point where I wouldn't recommend it.

All the same, noise and heat will be the main drawback, so the 1000 watts will be plenty and the performance will be great. You will need to plan it out a bit to ensure that you have good airflow in your case and spacing between cards. Liquid cooling will not be mandatory, just good airflow at a minimum. In general, this is a semi-complicated enthusiast setup you're contemplating, so take your time and do some research first.

 

[17seconds]

Some more info from Behardware.com. These comments are for a single 6990:


"Although the Radeon HD 6990 is discreet in idle, in load it breaks the record previously set by the GeForce GTX 480 in SLI and scores over 59 dB. Here the fan is running at full speed (4900 RPM).

Note that in 375W mode, noise levels vary between 52.8 dB and 59.4 dB. The fan runs at 3600 RPM at first and then, as the temperature goes up, accellerates progressively to 4900 RPM, with temperatures dropping after several tens of seconds and then the fan gradually dropping back down to 3600 RPM before the temperature starts to go up again and the cycle starts again. We therefore imagine that if your casing is well cooled, you should be able to keep the fan running at lower speeds. In any case, it’s a long way from being quiet!"
http://www.behardware.com/articles/822-3/report-amd-radeon-hd-6990-the-card-that-breaks-all-the-records.html

"As the Radeon HD 6990 releases half of the hot air into the casing, the components around it heat up, particularly hard drives, which suffer quite a bit as you can see in our report on the thermal characteristics of graphics cards, which has been updated with the full results for the Radeon HD 6990."
http://www.behardware.com/articles/747-22/maj-dossier-cartes-graphiques-degagement-thermique.html