OC psu i5 3570k sapphire 280x dual-x (no crossfire)

Matteo C

Honorable
Jan 31, 2014
19
0
10,510
Hi,
I'm going to buy a new computer and I'm undecided on which psu to buy to power this configuration
cpu: i5-3570k
mobo: Asus B75-plus
ram: 4GB Silicon Power 1333

I'd like to do some oc on the 3570k but I have no idea on the power requirements.
Thanks

ps: sorry for the crossfire in the tags but I don't know how to delete it