EVGA GeForce GT 610 01G-P3-2616-KR Video Card - 1GB, GDDR3, PCI-Express 2.0 (x16), 2x Dual-link DVI, 1x Mini-HDMI, DirectX 11 at TigerDirect.com

This card doesn`t even use a power connector, so ya, you could get by with a 400 watt, but I`d still try to go to at least 500.

Good card for the money.