Now, in power consumption, the idle power consumption is more or less same here, around 10W higher for FX series. But when you run an intense application which can stress all the cores, no doubt, power consumption is higher with FX series, but if the application needs long time, say in case of a video encoding from Bluray to X264 using hanbrake, FX-6300 will take reasonably shorter time period. So overall power consumption in this case might be similar if you consider the total period of time, the application is running.