HD 6970 2GB or GTX 580 1,5GB

[forceunleasher]

I don't understand how to choose a PSU If there are more 12v rails it's better or what?

 

[Stuka87]

I don't understand how to choose a PSU If there are more 12v rails it's better or what?

Single 12V rail is the best. That way you don't have to worry about overloading one rail, while the others sit there doing nothing.

Here are a few:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817151107

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010


Or if you want some extra headroom, here are some 850W:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139011

http://www.newegg.com/Product/Product.aspx?Item=N82E16817151102


And yes there are cheaper power supplies out there, but you get what you pay for. And when you have that much money in components, don't cheap out on the power supply.

 

[MrK6]

I don't understand how to choose a PSU If there are more 12v rails it's better or what?

Read reviews at jonnyguru.com . Not only will it show you what's good on the market right now, you'll learn a lot about how PSU's work. For starters, you want something that's efficient with good power distribution. I also like modular PSU's as it's easier to keep neater wiring. Multiple 12V rails is actually a smart safety feature when implemented correctly, but as Stuka87 pointed out, sometimes companies split them incorrectly and it power issues. Again, check out reviews at Jonny Guru's site, as he actually pulls the units apart and takes a look at how they're actually wired.

My favorite series atm are the Seasonic Gold and Platinum models. Unfortunately, NewEgg just finished a sale on them, but from time to time they do go on sale.

 

[forceunleasher]

Single 12V rail is the best. That way you don't have to worry about overloading one rail, while the others sit there doing nothing.

Here are a few:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817151107

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010


Or if you want some extra headroom, here are some 850W:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139011

http://www.newegg.com/Product/Product.aspx?Item=N82E16817151102


And yes there are cheaper power supplies out there, but you get what you pay for. And when you have that much money in components, don't cheap out on the power supply.

Thanks for the examples! so if I get the Gold Seasonic 850W it will be enough for an overclocked i5-2500k and two overclocked 7970's? It says in the description SLI ready and CrossFire ready.

Thanks, MrK6! I'll definately check that site out!

And thank you all for the answers, you really helped me out!

 

[BlavaFodia]

I'd get 7970. GTX 580 is too expensive unless you get a used one. If budget is not a concern for you, GTX 580 would be the choice.

GTX 580 is around $550 and HD6970 is $350

 

[Stuka87]

Thanks for the examples! so if I get the Gold Seasonic 850W it will be enough for an overclocked i5-2500k and two overclocked 7970's? It says in the description SLI ready and CrossFire ready.

Thanks, MrK6! I'll definately check that site out!

And thank you all for the answers, you really helped me out!

Yup, you should be fine. Unless you maybe plan on running furmark and prime95 at the same time with the cross fire setup for an extended period of time. They you may get over the 80% load mark.

But thats a good supply, and it should work extremely well for you.