I have (5) 6990's. Three of them are in a dedicated rig. Card #4 is in my main desktop rig, and card #5 will be going into another dedicated rig. I'm having an issue with card #5.
I have the following hardware:
Chieftec Dragon Case
650W Antec Earthwatts PSU
E6600 Dual Core CPU
6 GB RAM
60 GB OCZ SSD
My PSU only has 1 PCI-E power cable. Therefore, I bought a converter cable that turns (2) Molex connectors into 2 PCI-E power connectors. Perhaps this cable can't handle the load? I'm using this only, and NOT the PSU's own PCI-E power cable: http://www.newegg.com/Product/Product.aspx?Item=N82E16812198022&Tpk=CABLE-MPCIE4628
I have Ubuntu running with all my scripts and everything setup to run at boot time. But whenever the machine starts up, it immediately powers off, then automatically reboots. (as if someone pulled the power plug)
This occurs when the 6990 card is both in BIOS position #1 and #2. Is it possible that the 650W PSU isn't enough for (1) 6990? My plan was to run the 5th card with the extra hardware that I had lying around, which is what I'm trying to do now. From what I've read, a 6990 will use 375W in position #1 and 450W in positon #2. Surely I should have enough power for a small SSD and MOBO/CPU left over, even @ 375W.