I have a microATX system with AMD X2 5000 (AM2), 2 GB DDR2 (two sticks), One Wireless card, One PCIx1 TV tuner card, One DVD R/RW drive, two 120mm case fans and three 7200 rpm HDs. THis setup is in Antec NSK 2480 with 380W PSU and only for TV/DVD watching. I want to add ATI 4670. According to eXtreme Power Supply Calculator Lite v2.5 my total requirement is 305W. However, GPU specs require minimum 400W PSU. Do you think I am OK with 380W power supply? Since my requirement is only 305W, I think 380W PSU should be sufficient. Or, it has to be minimum 400W? I would appreciate your comments. Thanks.