GPU Computing - # of GPUs supported

Discussion created by ardo on May 25, 2010
Latest reply on Nov 19, 2012 by narada
Issues with GPU support when using over 4 gpus.


I currently have a desktop with 6 GPUs ( 3x HD 5970s ) in non-crossfire mode. Unfortunately, it seems that Windows 7 64bit only supports up to 4 GPUs. I have not been able to find a reliable source to deny or confirm this.

If windows 7 has this limitation, is there a Linux flavor that supports more than 4 GPUs?

In-case you are wondering, this is not for gaming but high-speed single precision computing. With this current setup ( if I can find 6gpu support ) I am looking to reach 13.8 Teraflops.

Also, my motherboard does support 3 16x pci-xpress gen2 slots... and I have a 1500w powersupply plugged into a 20amp outlet. Windows is able to detect all 6 cores.. although, 2 of which displays the warning "Drivers failed to load". I am using the latest drivers ( as of today, and the most recent version of ati stream sdk - 2.2 ) 

To recap:

- Can windows support 6 GPUs?

- If not, does Linux?

Thank you.