You need to reduce the voltage in the bios. a 390 can pull 300 watt each.

300 * 6 = 1800watt. (won't work on a 1300W psu)


You have 2 psu's. But you can mod the card to use 180watt each with a bios mod. Then you can run 6x 390 on a single 1300w psu

If you get code 43 errors there is a registry patch on the net you can run. (Run the exe as administrator, check the mod registry checkbox and click mod )


https://bitcointalk.org/index.php?topic=712228.0