Verified answer

The *minimum* power supply needed for the HD 5770 is 450W. It requires a 450W or greater psu.

http://www.amd.com/us/products/desktop/graphics/at...

If you think you might overclock the FX-8320, add another 150W.

The ati graphic card is a power hungry one i wouldnt use a 400 watt psu for those specs a sudden peak in power draw can destroy the psu i would suggest a 600 watt psu for that build maybe later get a amd hd 7770 a more engery efficent graphic card that doesn't use much power unless into heavy gaming or rendering

400w is not enough for your graphic card. HD 5770 need at least minimum 450w. I would suggest you to buy 500w or higher. If you insist to use 400w to run your pc, then your PSU will be damaged.

You do know there are several websites that you can put your computer's information in and will return with what the minimum PSU wattage you need to run it.

never get the minimum wattage always have power to spare ,the minimum power supply will always run hot and heat is death to a supply