Buying new graphics card

[Wayoutthere]

Hey guys, I'm looking into the possibilty of getting this graphic card (http://www.ebay.com/itm/SAPPHIRE-100354OC-2L-Radeon-HD-7870-GHz-Edition-2GB-256-bit-GDDR5-PCI-Express-3-/380759894831?pt=PCC_Video_TV_Cards&hash=item58a70eeb2f) by the end of the day. The only problem is that i don't know if it would work on my pc. I have no idea how many watts my pc can handle. It's an ASUS essentio series CM6730-08 desktop that came with a gt 630.

 

[MysteryINC]

http://www.asus.com/Desktops/Essentio_CM6730/#specifications

PSU - 350w PEAK so it can't handle a 7850.