Is +5VSB necessary when computer is off?

[Match]

I understand it's used to power on the computer. Is it necessary for it to remain on all of the time though? The BIOS chip has a battery, so it doesn't lose information if you pull the plug on the computer. I've read that the +5VSB rail allows you to use features like turning on the computer by hitting a key, using a NIC to bring it out of standby, or using Windows standby mode. I'm trying to figure out if I can turn off the power switch to the surge protector my computer's plugged into, when the computer's not in use for an extended period of time.


Edit: 4/6/05 I'm editing instead of posting and thereby bumping a now dead thread. Thanks for the replies!

 

[Matthias99]

It's *standby* power. It's there to be used when the system is nominally "off" but still powered, for things like Wake-On-LAN. Note that in "standby" mode, the PSU is still "on", but everything except the CPU/RAM is shut down, and those are put in a low-power mode (so you're not using the +5VSB rail in that case).

Unplugging the computer entirely won't do anything; the BIOS, as noted, has a battery backup. If you unplug it for weeks or months, the BIOS battery may die, but that won't do anything more than resetting the BIOS would do.

 

[MrControversial]

You can disable the 5VSB by simply shutting off the power supply via the switch on the back (in the case that your model has one).

 

[Zepper]

Nothing will be hurt by removing all power from the PC except it may shorten the life of the CMOS/RTC backup battery a bit as a well designed circuit will keep the battery from expending any current when the +5-SB is present.
. You also want to have the +5SB present if you want to use the Wake on Ring, Wake on Keyboard, Wake on ??? features.