Power supply wattage?!?!?!?!?

[Dougales]

Im trying to find out what wattage is needed for my build. i dont want to go way overboard but having some headroom would be nice.

Specs of the build are as follows:
Sabertooth z77 OR Maximus V Formula (im undesided)
Corsair Vengeance 32GB Kit
2 1.5TB WD HD
1 Intel 520 (128GB)
2 Sapphire HD 7970 OR 2 GTX 680
LG Bluray 3D burner
D5 Pump
4 UV Cathodes
3 120 MM fans
1 240MM fan (comes in case).

i was thinking around 1000W but i dont know if i will need more or if i could go with less. any help would be appreciated.

[Jbc223456]

Check this guide out.

[Dougales]

too old of links i guess... half the links are broken.

[glc]

Your limiting factor is going to be the number and type of PCI-E connectors if you are going to be using 2 cards. 750 quality watts should be enough, but it wouldn't hurt to have a bit more. I would probably go with at least an 850, preferably modular, and either Seasonic or Corsair HX/AX.

[Dougales]

i was looking at the corsair ax850 but i wasn't sure if that was going to be enough. i dont want the psu to be running at 80% load all the time though. will 850 be a prime wattage?

[Preston]

This might give you a ballpark idea: Newegg Power Supply Calculator.

There are other PS Calculators out there too (to get a "second" opinion).

[David M]

Originally Posted by Dougales i was looking at the corsair ax850 but i wasn't sure if that was going to be enough. i dont want the psu to be running at 80% load all the time though. will 850 be a prime wattage?

High quality PSU's, like what glc listed, can easily sustain that percentage of maximum load. They are engineered for doing this. It is the junk PSU's that cannot reach their maximum claimed load or have other problems such as not being able to keep the correct rail voltages at high loads. This is two of a number of reasons why the experts here only recommend the highest quality PSU's

[Dougales]

Originally Posted by Preston This might give you a ballpark idea: Newegg Power Supply Calculator. There are other PS Calculators out there too (to get a "second" opinion).

that calculator estimates my system at 748W under full load. so assuming that i am doing a stress test or something stressful for the computer what wattage should i get so when i use it the power supply doesn't reach its max load (ive heard that if you dont put it under full load all the time it will last longer)

[David M]

If you are nervous about it and the calculator has it that close to 750 watts then I would get the 850 watt unit. The piece of mind is probably worth the extra money, even if you might never need the additional 100 watts. That's what I would do in your situation.

http://www.newegg.com/Product/Produc...5&Tpk=850%20ax

http://www.newegg.com/Product/Produc...1&Tpk=850%20hx

For a 10 dollar difference you might as well get the AX.

Gaming computers are never under a full load all the time unless all you do with your computer is to run stress tests on your graphics cards all day long. You probably want to run a few stress tests on your system after you get it up and running to make sure it is going to work under a worse case scenario for your PSU and graphics cards.

Have you considered a 690 instead of two 680's? This would be more power efficient and the total graphics processing power is about the same, with two 680's being only slightly faster. I don't think the difference was worth it. The single 690 would also be less expensive. You would also not have to run SLI. I saw this info in a review of the 690 comparing it to two 680's.

[Dougales]

OK! Thanks, and corsair and silverstone are the highest recommended?

[David M]

The high end HX and AX Corsairs and the Seasonics...like glc said.

[jdeb]

Seasonic X850 GOLD

[birddog_61]

Actually good PSU's like the seasonic and seasonic made corsairs run at their most efficient at around 80% load. That is why you don't want to buy a 1200 watt psu when you only need 450, it won't meet its efficiency rating at that low of a load. My personal opinion is I like to be between 65%-80% load on a psu. So with an 850w psu I want between 550w to 700w of draw, so if its a gaming build I try to get the idle power consumption at the low end (65%) that way when the gpu is at full load it doesn't go over 75-80%.