You don't need multiple , identical threads. My advice in this thread stands. The reason no one has posted after me was that not only was I correct I showed you the best power supply for the money with the Seasonic X 850.
http://www.tomshardware.com/forum/354032-28-enough-power-connectors
Review. Hardwaresecrets Golden ( highest ) award. Notice they easily pulled 1000 watts from it.
http://www.hardwaresecrets.com/article/Seasonic-X-Series-850-W-Power-Supply-Review/1169/10
2 x GTX 680s need a recommended 800w power supply.
http://www.realhardtechx.com/index_archivos/Page362.htm
But some power calculator told me I need 1000 watts. Nope. Online power supply calculators err on the side of caution because they are expecting you to buy a crap brand like Coolermaster or Thermaltake or worse that can't produce it's rated voltage. As we see from the Hardwaresecrets test this unit provides 150 watts over rated voltage with no problems. Online calculators also factor in something called capacitor aging. This adds another 20% usually to what it recommeds. Capacitor aging is a thing of the past with new high quaity solid Japanese caps in all high quality power supplies.
So how muh power does a system with 2 x GTX 680s actually use?
This setup is with a 6 core i7 3960X. At full load using Furmark ( your computer will never pull as much as with furmark. Nvidia and AMD call it a heat virus ) that 6 core system pulled 573 watts.
http://www.legitreviews.com/article/1891/12/
From Guru3d.
" Here is Guru3D's power supply recommendation:
•GeForce GTX 680 - On your average system the card requires you to have a 550 Watt power supply unit.
•GeForce GTX 680 SLI - On your average system the cards require you to have a 750 Watt power supply unit as minimum. "
http://www.guru3d.com/articles_pages/geforce_gtx_680_sli_review,4.html
'
I can find you 8 or 10 more benchmarks showing that 750-800 watts is fine for your system if you want. The Seasonic X is one of the best units from one of the best manufacturers on the market.