Re: PSU for 670
From EVGA's website: PSU requirement for gtx 670:
Minimum of a 500 Watt power supply.
(Minimum recommended power supply with +12 Volt current rating of 30 Amps.)
Your specs of your antec 500 earthwatss:
+3.3V@25A, +5V@24A, +12V1@22A, +12V2@22A, -12V@0.8A, +5VSB@2.5A
You could try it with your 500watt psu. I don't think it can hurt the card.