How big PSU do I need?

jomari29

Honorable
Apr 9, 2012
154
0
10,690
Hey guys, Im planning to change my PSU to modular
I currently have a Corsair 750 watts PSU, Non modular (Hate it)

Is the new Corsair HXi PSU line good?
if so, should I get the 750 watts or 850 watts

my pc

i7- 4790K OC 4.6GHz
AMD HD 7950 OC 1.2GHz (will change later to GTX 970)
8GB RAM
5 140mm chassis fans
1 HDD 2 SDD

$15 more for 850 watts worth it? thanks!