GTX 770 reccumended power supply

Hello everybody my friend just bought new graphic card GTX 770 and he needs to buy new power supply because the old one is 500W so he wants to know what power supply he should get. Thanks !

The old 500W might be ok to power it. Depends how "old" it is.

But if you're looking for an appropriate, quality, cheap unit; the XFX 550W will handle it really well.