Power Supply Help

[Jordiscroll]

Hello,

I'm going to build a new homebuild systeem soon and I have question about the power supply.
I have used Neweggs PSU calculator it says I need at least 851W for this set up
but eXtrme Power supply calculator says I need at least 666W

It's a big difference so thats why I'm asking it here

What do I need for the set up mentioned below?

2 x MSI N570GTX Twin Frozr III
Asrock Z68 Extreme3 Gen3
WD Caviar Blue WD5000AAKX
Corsair Carbide Series 400R
LiteOn iHAS122
Corsair Force Series 3
Intel Core i5 2500K
Corsair Vengeance 1600Mhz 4x2GB
Corsair H100 Liquid CPU Cooler


Thanks for you help!

Jordi

 

[ko888]

For a system using two GeForce GTX 570 graphics cards in 2-way SLI mode NVIDIA specifies a minimum of a 800 Watt or greater power supply that has a combined +12 Volt continuous current rating of 56 Amps or greater and that has at least four 6-pin PCI Express supplementary power connectors.

Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Total Continuous Amperage Available on the +12V Rail(s) is the most important factor.

Overclocking of the CPU and/or GPU(s) will require an additional increase to the combined +12 Volt continuous current rating, recommended above, to meet the increase in power required for the overclock.

 

[Jordiscroll]

OK so a Corsair Professional Series HX850W will work for sure... but how about the Corsair Professional Series HX750W
I heard the 750W Corsair can handle more then 750W, not sure if this is true.


And what happens when I run 2 570's on 750W and it is not enough? does the system just shuts down or is it going to stutter then?

Jordi

 

[ko888]

If you draw more current from the +12V rail than the power supply can deliver you may trigger the OCP (Over Current Protection) circuit and the power supply will shut down.

If the graphics cards don't receive sufficient power then its 3D performance will be throttled or you can experience spontaneous system reboots or freeze-ups or BSODs.

If you don't run FurMark or OCCT GPU:3D or similar GPU stress testing tools then the Corsair Professional Series HX750W will work fine.

If you want your system to be able to run FurMark or OCCT GPU:3D or similar GPU stress testing tools, for whatever reason, then you will need the Corsair Professional Series HX850W.

 

[Jordiscroll]

Ok! Thanks for your help
I think it's better to spend the extra money and go with the 850W just to be safe.

I'm going to build this computer this summer I think, maybe i'll change some parts when new things come out.

Thanks again for your help

Jordi