I use Corsair HX850W with 80+ silver standard for 2 SLI and OC every single component I am able to do on my PC. This PSU is at the highest blowing out a comfortly summer brees air at the back even thus I have tried to fry it as much I ever can do with OC, the fan is soundless. All top-high-end product into the single circuit! Corsairs PSUs is always thought to transfer more W then what it is written on the spec, am sure my PSU can transfer up to 1000-1200W without complaining at all. Recommend you to buy a Corsair PSU with 80+ standard. Happy hunting!