Help buying a new PSU. ATX12V standards?

[vntg]

Im looking to buy a new psu.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139012

One of them is ATX12V / EPS12V and the other is ATX12V v2.2 / EPS12V 2.91.
What is the difference as far as compatibility with my system? Does it matter which one I get?

I am using a GIGABYTE GA-EP45-UD3P LGA 775 motherboard with an Antec 902 case.

 

[hunter315]

They are both great PSUs, as long as its ATX12V it will work fine with a modern motherboard, the EPS specs are for servers and other mission critical systems, its also where the 8 pin motherboard connector comes from. Either one will work quite well. The 650HX is slightly newer and slightly better, but once you get into that range of performance its just tiny differences in ripple and voltage stability that dont affect the end user.

 

[vntg]

Great, thank you. And yes, I think I will get the 650HX as it is modular also.