Can my psu handle the gtx780 and which version should I pick

[ImTrueSkillZ]

Hello.

I have a Seasonic S12II-620 Bronze 620W PSU but I'm currently running my old radeon 5750hd graphics card, if I upgrade to gtx 780 ?

The gigabyte website says: System power supply requirement: 600W
but my question is... if some how I get my cpu and gpu(gtx 780) to work at full power, will my 620W psu hold it and won't shut down?

I'm picking either the the gigabyte's edition or the asus one.

If I won't have any problems, which one do you suggest I take?

(I'll be running 2 monitors)

http://www.gigabyte.eu/products/product-page.aspx?pid=4673#ov
http://www.asus.com/Graphics_Cards/GTX780DC2OC3GD5/#overview





PC specs:

CPU: Intel i7-3770k 4.0GHz
CPU Cooling: Cooler Master Hyper 212 EVO
RAM: Kingston HyperX Blu 1600MHz 16GB
GPU: Asus Radeon 5750HD
Motherboard: GIGABYTE GA-Z77MX-D3H (rev. 1.0)
System storage: Kingston 60GB SSD
Data storage: WD 1TB HDD
PSU: Seasonic S12II-620 Bronze 620W

Monitor #1: LG W2253TQ 22'
Monitor #2: LG 22EN43 22'

 

[ferwindjacks]

Yeah it should be able to, I'd say minimum wattage is around 450-500 off the top of my head.