Topic: Help with balancing 2x PSU on a miner with 6x R9 270 (Read 542 times)

Hey, have built a new rig with the following components:

Gigabyte GA-990FXA-UD3
1 x 750W 80 + Gold (2 x 12V 30amp rails
1 x 1000W 80 + Gold (4 x 12V 18amp rails)
6 x ASUS Radeon R9 270 OC
Add2PSU adapter

Have now built it together with 6 powered risers x1-> x16. But I've been thinking about how I should balance the PSU's. Somewhere I read that if you run with 2 PSU so should you run 6pin + molex on risers from the same PSU for it to become stable. So on my rig I run as follows, 3x6pin + 3xMOLEX on both and motherboard at No. 1. The computer will boot up fine, all 6 cards found in BAMT 1.4 so all good so far, but when I start the mining, PSU 2 shuts off and screen goes black. I guess it depends on the cards draws to much power from the motherboard to the PSU one overloaded?

Here is a picture from my initial configuration
http://imgur.com/fwreY2P

I have tried the following without success:
*Changing place between PSU 1 & PSU 2
*All 6 x 6pin from PSU 2 and the rest on PSU 1.
*All 6 x 6pin from PSU 1 and the rest on PSU 2.
*2+4 / 4+2 and so on. All the same problem.
*As a final attempt i cut the 12V lines on the powered risers to ensure that the cards didnt draw to much from the motherboard (as decribed on link #1).

I have googled ALOT and browsed the forums, and there are some usefull information here but i cant make it work anyhow. I guess it all about balancing the power over the rails.

Links:
#1 - https://litecointalk.org/index.php?topic=11818.msg88623#msg88623
#2 - https://litecointalk.org/index.php?topic=6171.msg47616#msg47616

Please let me know if you have any ideas!