Quick PSU question

Yesterday i unknowingly purchased a pc chassis which includes a PSU which is (420W peak)350watts. It says 12v1&12v2=276W. Will it run my system? if not how many watts do i need? Also what do you think about the system
My newly purchased system is as follows: Asus P5Q-E, E8400, 9500GT, 2x2 4GB 1066DDR2 ram, 2x750GB (7200RPM)HDD on raid0 and 1x 1TB (7200RPM)HDD with more hdd to be added. ps: i dont intend to oc.
As i already purchased everything i need quick responses to be able to return these goods.
thanks in advance!!

like full metal said, it depends on the brand. i wouldn't use it unless it a normal name brand like corsair. usually those psu's that come in the box with a case are junk. if i were you i wouldn't use it. the last thing you want to have happen is a junk psu fries the rest of your components.

Swap the PSU out for this one, you can just pull the one out of the case and put this one in.
http://www.newegg.com/Product/Prod [...] 6817139008

thank you!
PSU came with a gigabyte GZ-X7 case but i can not see any brand name on it.
i will return the gz-x7 and purchase a known brand at minimum 550W

I like the 400cx Pick for that typical card better. Doesn't need much else, unless he's going to upgrade the card soon, I wouldnt go anymore than a 400cx.

no, OCZ, antec, corsair, seasonic, PC power & cooling, and a few others will NEVER rate a PSU at peak, any halfway decent PSU will be rated at continuous power which is what you really want, those that rate at peak tend to fail PSU reviews miserably.

Cooler master makes some pretty good ones, there are better brands but with your options its pretty good.

Silverstone / CoolerMaster is the best choice.

Silverstone is expensive and an oldschool psu, most split rails but, pretty solid.

Where do you live?

Do you ever plan to sli?

btw mobo supports crossfire only(i suppose)