Power supply running power when I shut down?

I have a Corsair CX750M PSU.. These units remain on even after shutting down my system so, should I flip the switch off when I'm not using it or, is it safe to leave that switch on? Thanks!

What do you mean by "remain on?"

Even when you shut down the system, all PSUs supply a small amount of standby power so that the motherboard can wake itself up (e.g. through USB, wake-on-LAN, RTC alarm, etc.). If you turn off the standby power then you will lose those wake triggers.

Always leaving the switch on is by design. If you like, you can save a few watts of power by switching off the PSU at the expense of draining the coin battery faster and increasing the time needed to boot up (since after you flip the switch it will take some time for the PSU to power up and stabilize the standby voltage rail, then it will take some time for the motherboard to power up and complete the standby power sequencing, then the motherboard can actually start booting up).

So, the switch is supposed to remain in the "on" position by design. That is ALL I needed to know. Thanks a lot!!!

The handshaking between the PSU and motherboard takes only a fraction of a second and is not an issue. I always turn off any appliance such as a PC when not in use at the mains. Not to do so is a fire risk as any fireman will advise you.

Steve C said:

The handshaking between the PSU and motherboard takes only a fraction of a second and is not an issue. I always turn off any appliance such as a PC when not in use at the mains. Not to do so is a fire risk as any fireman will advise you.

Are you saying that you think that turning off the power supply all the way down is best. What about the drain on the battery was mentioned?? Is that not true???

Leave it plugged in.
After 10 years, unplug it and buy a new computer.
During the intervening 10 years, just use it.
No worries. None at all.

Steve C said:

The handshaking between the PSU and motherboard takes only a fraction of a second and is not an issue. I always turn off any appliance such as a PC when not in use at the mains. Not to do so is a fire risk as any fireman will advise you.

As a former fire fighter......simply turning off at the mains is not factually correct.....They must be unplugged at the source....and only then will a surge/power spike/lightning strike wont be the cause of a fire....at those particular devices.

Ditto plankton. Historically speaking the older AT-type computers had a front-panel switch that connected directly to the power supply. The newer ATX-type computers are set up with the power supply being controlled by the motherboard, the On|Off switch is connected to that board and only tells it to start the bootup process. There should be a small light on the motherboard when there is power to it, hence it always being actually on. This leads into the necessity of pulling out the power cord and letting residual power drain off before making any changes inside the case.

The OP is referring to the mechanical switch on the back of some ATX PSUs, which does cut off mains power. Turning off the switch still leaves the PSU grounded so it's more convenient than unplugging if you're working inside the case.

The specific fire risk of leaving your PSU turned on all the time is about the same as leaving your alarm clock, microwave, or TV plugged in all the time. While I agree that it's non-zero, that's a risk I am willing to take in the name of convenience. If you live somewhere with poor wiring or frequent surges then there are probably better things to do than individually turning off appliances.