PSU for 2 x 6970 + 2 x 6990 (liquid cooled)

[cvicisso]

Any ideas how big of a PSU I'll need for such a beast?

[1713964453]

1713964453

[1713964453]

1713964453

[1713964453]

1713964453

[qed]

Get a second motherboard is the only solution. You will most likely fry the pci express slots.

[sc8nt4u]

Get a kill-a-watt.

I've been overestimating my power consumption before I bought a kill-a-watt. Before I bought my kill-a-watt, I estimated my systems to be consuming 1450w~, but really the two systems below pull 1100w together. Note that I undervolt and overclock my GPUs. I've tried to lower CPU voltage as well, but really you're not saving that much power.

1x i7 930 @ 2.8ghz 1.184v (3 cores disabled)
2x 5970 @ 750/300 1.00v (333 Mhash/ea)
3x 1TB Samsung F3
1x 90gb Vertex 2
2x 2GB DDR3
ASUS P6T SE
Xion 1250w

1x Sempron 140 @ 2.8ghz .95v
3x 5850 775/300 @ 1.00v (310 Mhash/ea)
1x 2GB DDR3
1x Random HD
PC Power and Cooling 610w PSU

2.262 Ghash for 1.1kW is pretty efficient.

[padrino]

Get a second motherboard is the only solution. You will most likely fry the pci express slots.

Use extenders with molex to offload the slots or get a board built to support 4 x16 cards (specifically calling out triple SLI or quad nvidia) as it should be built to push the load.

[shakaru]

Do this
Required items
2x PSU
1x Electrical tape.
1x Wire stripers


Take the first psu that will goto the board and locate the green wire on the 4th pin and any ground
on the second psu do the same but cut the wires at the atx connector.

Strip the two wires on the 1st psu a bit so you can attach the power on and ground to them.
Seal splices and TADA. DUAL PSU

[dinker]

This one should do it!   

http://newegg.com/Product/Product.aspx?Item=N82E16817256054&cm_re=power_supply-_-17-256-054-_-Product