400 watt psu

Can this PSU support this GPU on a system with many old hard drives? Specs: CPU - FX 6300 4.1ghz @1.3875 volts RAM 16GB 1333mhz Motherboard - Gigabyte GA-78lmt-usb3 or something like that I don't have the PC with me to be exactly correct. The point is this is a low end motherboard and I can't...