is it bad to leave mine on all day

Mine's been on almost constantly for over a year -- the only time I put it to sleep is when I move it; I restart it from time to time, but I've never actually switched it off -- and I've had no problems with it.

Well... it's not "bad" as such. If you are not using it, however, why would you want to leave it on? If you are using it, then there's no harm in leaving it on. Do consider that components which are susceptible to wear (e.g. the fans)will be running 24/7 which will cause them to reach their failure point sooner. Fans tend to have a very high mean time between failures... so even leaving it on 24/7 should not cause a fan failure within the normal life of a laptop (I'd say about three years).

Just as a general rule... if you're using it... fine... leave it on... If you're just leaving it on for the sake of leaving it on... then there's not much point in that.

Actually the fan failure rate in my experience on MBPs has been 100%. I've two of them and have had to replace 3 fans to date and have one on backorder as we speak. That said, I've always been a proponent that it is harder on electronics to start up than it is to just let it idle. Also, the Mac OS X does routine maintenance while the MBP sits idle (usually in the wee hours of the morning), but you can 'force' such maintenance with a utility like Onyx or Cocktail.

I leave my notebooks on all night sometimes since there are cron jobs that I have that run at around 2 AM that sync things from my laptop to my server and vice versa.

I've had Dell laptops at work that never get shut off for months at a time (I shut them down if I'm not coming in for the entire weekend or when I go on vacation) and they're up and running just fine... I'd hope the MBP could do the same and not have issues. Otherwise I'm going to switch to Dell for my personal notebook when the MBP bites the dust! 🙂

I've had similar experiences with my ol' trusty PowerBook and I leave my MBP on continuously. As for waiting for the MBP to bite the dust, welcome to the world of Apple computers. The average lifespan of an Apple computer is over twice as long as the nearest competitor. My 2001 model iBook, which saw me through three years of seminary, my daughter through a year of undergrad work is still being used by my grandson today. Nearly seven years for what can reasonably be called a 'consumer' model laptop isn't bad.

Welcome! I've used both Apple products and other PC names over the years (far too many to count...can you say "MainFrame"?) and while anything man made will break, the thousands of Macs I've worked with have had a consistently better lifespan and quality than any other brand. Again, welcome to the fold.

The CFC light in the display will generally be the thing that wear out first, and that's not sensitive to power-cycling as it is to simply being lit.

Most of the electronics ought to handle things just fine. Laptop power is lower than a desktop, and the power supply is small and external. The power switch is a soft-power on routed through a chraging circuit, so the power "surge" that might be harmful in a desktop being switched on is much reduced.

That said, if you aren't using it, you'll save display-life hours by putting it to sleep when you aren't actively using it. Sleep mode is quite safe and the system can remain in the sleep state for days on battery power and indefinitely while it's plugged in a receiving power. In sleep mode, it uses about 5% the power it does when it's awake.

best left on in my view.

Electronics on the MBP board keep to a stable temp and don't suffer from thermal stress which reduced component life when switched on from a 'cold state'. Also, routine Unix tasks run during the early hours for clear log files etc which helps maintain system performance.

Maybe get the screen to power off and 'put hard disks to sleep' in the 'Energy Saver' icon, keeping disks spun up certainly reduced Disk Drive life.

Hope it helps ya,

Nick B 🙂

NickiB wrote:
Electronics on the MBP board keep to a stable temp and don't suffer from thermal stress which reduced component life when switched on from a 'cold state'. Also, routine Unix tasks run during the early hours for clear log files etc which helps maintain system performance.

Please note that starting partially in Tiger and more effectively in Leopard, the move of Unix maintenance tasks from cron to launchd means that OS X should be running a check on the log file routines every time you wake the computer, and running them if they have been missed, and therefore these quick maintenance tasks should no longer be a reason for leaving a computer running for so many hours overnight. (There is some debate about how well the current arrangement is working, but Apple clearly doesn't intend to require a disproportionate number of overnight power-on hours just to run a 2-minute script or two.)

It makes more sense to justify continuous power-on from the standpoint of consistent temperature and power level. On the other hand, laptops are made with the expectation that 95% of users will close, transport, and open them throughout the day, because that's why they bought them, and therefore, since the normal expected use of a laptop makes 24/7 power-on operation nearly impossible, I don't worry about it. Given that typical user scenario, I figure that that the design spec of a laptop assumes multiple daily thermal and power stresses, so it had better be able to deal with it. And most laptops don't fail under this normal use case.

That said, I think it's good to avoid thermal and power cycles as much as is reasonable. After arriving at home or work, once I turn on the laptop, I generally leave it on. I set my display to sleep after about 90 minutes. The goal with that is to balance backlight-on time with the frequency of power cycling of the backlight, because some have posted that fluorescent bulbs last longer the less you cycle them. I think it might be bad to have such as short display sleep time that the backlight goes off and on a lot.

My PowerBook G4 sleeps at night. It's over four years old and still going strong.

That's definitely good to hear being that I'm new to the Apple world.

Why not just have the display sleep then?