I have to choose between these psu's
HX650 is a gold rated power supply and is modular(all cables are removable except 8pin and 24pin which have to be used )
TX650 is a bronze rated power supply and IS NOT modular(all cables are hardwired)
TX650M is the regular TX650 but it is semi-modular(some molex and sata cables are hardwired too)
I hope this helps!