OT - for the Mac users

The hardware is not that different, but in sleep mode it'll be using so little power it won't noticeably warm itself. It doesn't make much difference. Macs usually start up *much* faster than Windows machines, so there's not the same inconvenience involved in having it off when you need it on.

Printers can use a lot more power than computers when they're simply sitting there waiting to do something.

The last computer I used where keeping it on was really important was an ICL/Three Rivers Perq workstation back in the 1980s. The disks would often expire if they stopped. And those things used about a kilowatt each.

==== j a c k at c a m p i n . m e . u k === ==== Jack Campin, 11 Third St, Newtongrange EH22 4PU, Scotland == mob 07800 739 557 CD-ROMs and free stuff: Scottish music, food intolerance, and Mac logic fonts

I shut my Mac laptop off after every use. It starts so quickly that it is almost as if it is on. On the other hand my wife shuts her pc off , and it is like waiting for the second coming to happen before hers is ready to go again. Just from a mechanical standpoint, I am supposing that any wear and tear on the computer from starting and shutting down, would be less than starting and leaving it run indefinitely. All those little bearings spinning endlessly would wear out faster, if left on, it seems to me. But maybe it is different with computers, than other engines. Most engines, seem to have maintenance intervals based on time run, rather than time owned.

John

I have an iMac. The suggestion is to leave it on unless you are not going to use it for several days. It will be quite happy in sleep mode.

Martha

The Mac does some of its system maintenance at night, so it's good to leave it on overnight at least once in a while. Keeping it warm is NOT an issue with the Mac. (I put mine in sleep mode to save energy.)

We have only ever had Mac's at our house. My husband is THE Original Computer Geek! LOL So.... I have been trying to understand for ages, why we have to leave the computers on all the time, he has explained it to me, several times, and I never completely "got it" and when I saw this thread, I kept watching to see if somebody else here "got it"....

so he just tried to explain it to me again, this is the part I "got"...

tin whiskers. Yep, you read it here, Tin Whiskers.

Something to do with the electrical surge each time you charge (turn on) and discharge (turn off) the CPU.....blah, blah, blah, creating some neo atomic stalagtytes and/or stalagmytes which over time, touch each other and short circuit the CPU's brain, blah, blah, blah.....

I think it's what happens if you go to kiss your husband good night and he hasn't trimmed his moustache recently and you get one of those yucky fuzzies. Yep, that's got to be what it is.... tin whiskers!

I used to think I was pretty intelligent, but sometimes he can really make me feel like such an airhead!

I think I'll just keep leaving my Mac turned on.....as the bumper sticker says, "I leave my Mac turned on, and it returns the favor!" Ha ha ha.

Tina, on the Mac mini tonight

Yep, tin whiskers do really exist - they can slowly grow from the solder and eventually could cause a short circuit. Tin whiskers are also more likely to grow from lead-free solder (that's lead the metal, not lead as in cable ;-) ) Guess what sort of solder now has to be used in almost all industries in the EU - that's right, lead free (and chances are that the manufacturers have switched all their computer boards to lead free - why run 2 systems?). So with newer computers it is more likely to become a problem :-(

Lizzy

I'm a bit late answering this, as I've had a major problem lately (dead logic board -- to the tune of $1025. I'm *so* glad for AppleCare, which meant that I paid exactly $0 for the new logic board, though I was without my computer from Saturday to just about an hour ago.

Anyway, leaving your computer on is actually not a bad idea. For one thing, the OS will run certain "routines" overnight to make sure that everything is working right; they don't run otherwise. Some of those routines are daily, some weekly, some monthly.

That said, sometimes a restart is a good idea, just to clear out stuff from temporary memory or to free up RAM from being used.

So I'd suggest that you should leave it on *most* of the time, with occasional restarts. That's what I do.

That was true with versions of MacOS before OS X, it isn't the case any more. (You can always schedule certain activities to happen in the middle of the night if you want, but the system doesn't do that for you).

The issue of whisker formation is actually backwards from the way it was described here. The longer the machine is on, the more the solder and silicon will migrate to places they shouldn't be, so keeping the machine off when it isn't in use will help prevent this problem. The only things that don't like frequent stops and starts are moving parts, like switches and disks.

==== j a c k at c a m p i n . m e . u k === ==== Jack Campin, 11 Third St, Newtongrange EH22 4PU, Scotland == mob 07800 739 557 CD-ROMs and free stuff: Scottish music, food intolerance, and Mac logic fonts

And fans... But they don't like to be on constantly either. Ever had to pick chunks of disintegrated fan out of your heat sink?

Also, if the machine is switched off, it's less likely to he hijacked for nafarious resmailing purposes...