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Old April 12th 10, 02:32 AM posted to alt.comp.hardware
~misfit~[_15_]
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Default More or less safe to turn off power supply rocker switch?

Somewhere on teh intarwebs Nicholas Dreyer wrote:
On Fri, 09 Apr 2010 19:08:51 -0400, Strobe wrote:

On 09 Apr 2010 03:26:08 GMT, Nicholas Dreyer wrote:

I keep my PC on for at most a few hours a day. After it has powered
down, is it safer to shut off all power to the motherboard using the
toggle switch on the power supply, or is it better to leave it on,
or does it not matter at all?

Thanks for any advice, or pointers to some useful studies on the
matter.


For ultimate power economy, use the switch - modern PSUs continue to
provide 5v when the PC is 'off'..

To *really* economise, switch off with a cheap external power strip
- it's cheaper to replace that than a PSU when the switch eventually
wears out!

If you live in an area prone to lightning storms, it's safer to
actually unplug the PC when not in use - a nearby lightning strike
on the power line can easily jump over a power switch and *might*
fry your PC.

Of course, at most you'll save a few dollars a year... And many other
devices (TVs, microwaves, cable boxes) also suck power when they're
nominally 'off'.


Thanks all for the feedback that points to the advantages of complete
power off.

I was leaning that way, but my only question regarding that approach
would be: Is there any risk to the motherboard from regularly turning
back on the low-level 5v "soft power"?


Not so much to the motherboard but there's more stress put on the power
supply as the big capacitors 'fill', there's a big inrush current. In fact
the only times (twice in 15 years) I've had catastrophic failure (BANG!) of
(one of) the large capacitor/s in the PSU was when applying mains power to
it.

There is another consideration. If the machine is turned off at the back, or
unplugged, the small battery on the motherboard that retains BIOS settings
will die more quickly. However they're only a couple bucks (depending on the
brand and where you live).

What could be more of a PITA is if you have custom BIOS settings such as an
'on the edge' overclock or 'just so' RAM timings, or even if you're running
your HDD/s as AHCI (and the default is 'IDE emulation'). Then, when the
battery does go you have to know these settings so that you can re-enter
them when you replace the battery.
--
Shaun.

"When we dream.... that's just our brains defragmenting" G Jackson