I have this Antec TruePower Quattro 1000W, 4 x 25A rails, 840W total. This should be more than enough to power 4x HD6870 (140W each, two 6pin connectors each)?
12v1 - 12v EPS MOBO connector that power CPU and MOBO.
12v2 - modular connectors for HDD
12v3 - PCIe modular 6+2pin(y-splitted to 2 x 6pin) and 6pin
12v4 - PCIe modular 6+2pin and 6pin
Three cards was easy to connect, everything runs fine even with heavy OC.
To connect fourth card i made an 8+2pin to 6pin Y-splitter. Now I divided 4 cards to 3 rails like this:
12v2 - 3 PCIe connectors - load: 18A
12v3 - 3 PCIe connectors - load: 18A
12v4 - 2 PCIe connectors - load: 12A
I measured connector voltages, all are nicely +12.2volts (+/- 0.05v)
Four cards setup is pretty unstable, crashes every 4 hours even w/o OC. And cards OC much less than in 3 card setup.
Am I having PSU problems? And how do you guys connect your cards when there are not enough connectors?