Back in the dark ages you were warned to shut down your laptop if you were planning to move it since the disks might crash as a result of jostling. (We were told that shutting them down meant parking the disk drive heads and crashing was therefore impossible.)
Flash forward to 2015. Is this still the case for modern laptops? If I put my laptop in sleep mode can I throw it in my backpack and head out without worrying about it crashing? Not having to shut it down every time I need to go somewhere would be a real benefit. I assume they solved this problem years ago but I thought I would check since old habits die hard. I have a Lenovo T440 if that matters.
Not really, from what I’m reading. As long as the computer is on at all (S0 - S4), it’s writing something to the hard drive. Maybe if you have an SSD, though.
I’m pretty sure this doesn’t matter much – but if I’m wrong, let me know. The various sleep states determine the amount of power supplied to various minor devices, but in all of them the hard drive should be off. The moving parts (hard drive, fans) are the only vulnerable things, so the sleep states shouldn’t matter.
Where are you reading this? Sleep should always turn off the hard drive unless something is terribly misconfigured. Sleep works by keeping just enough electricity supplied to RAM, and sometimes a little to the CPU, so you can resume right where you left off. The hard drive is not involved. You can often check for yourself by listening to the “click” sound of a hard drive parking, and its mechanical whir stopping, and the fact that your battery is still usable several days later – a hard drive would use far too much power to keep on.
In hibernation (sometimes called “deep sleep” or similar, and confused a bit by features like “hybrid sleep”, which is an automatic sleep to hibernation timer), RAM is written to the hard drive and the computer is shut off completely after that. And even in hybrid sleep, memory is pre-written to the hard drive BEFORE sleep, so it can just smoothly transition from sleep to power off without re-waking the hard drive.
Anecdotally, I’ve had several laptops in the last decade that pretty much live permanently in sleep mode, never powered off completely. They stay in my backpack as I walk across college campuses, bike up and down hills, jog to the next class, etc. Never had a problem with any of them.
Apple also started putting a sudden motion sensor in their laptops more than a decade ago, which would quickly park the drive heads when the computer gets moved. So even walking around with the computer turned on is very unlikely to result in disk problems. I assume they’re not the only ones doing something like this.
An issue with sleep mode is power consumption is low, but not zero.
So sleeping your laptop before biking across campus would be fine. The HD is safe and the battery won’t run out in a few minutes, or even a few hours.
But sleeping it, then tossing it in a suitcase for a 30 hour plane trip halfway around the world might not work so well. Somewhere along the way the battery may die and if so the laptop will shut down the hard way. Which runs a small, but non-zero risk of data damage which you’ll discover after you recharge the battery & restart it.
Or worse yet, sleep it, leave it on your desk, then go on a 2-week trip someplace while it sits there. The battery will be dead when you get back.
Hibernation seems safe. I have a tower computer on my desktop that I hibernate whenever I leave. Even a power failure has no effect (so long as the power is back on).
With a reasonably modern laptop (2-4 years old), sleep can easily last 30 hours. The average laptop battery is about 50Wh, and sleep uses 0.2W-0.5W depending on processor, so that’s 10+ days with a new computer and battery or 2.1 days with an older computer and a battery with 50% of its max capacity.
That’s exactly what Hybrid Sleep (Windows Vista+, 2007 onwards) or “Safe Sleep” in OSX (2012+) is meant to protect. It pre-writes hibernation data to your hard drive and then puts it to sleep, so in the event of battery depletion it’ll just smoothly transition to hibernation with no data loss. The benefit over normal hibernation is that you can still recover quickly from sleep if the power didn’t go all the way out.
It’s on by default for Macs and some Windows computers, or you can turn it on manually.
*Tres *cool. One of the downsides of hibernate is the many seconds it takes to enter hibernation. Whereas sleep seems to enter much more quickly. Hybrid sleep will have slow sleeping but quick awakening. The additional safety is worthwhile for sure.
As to laptop battery life in sleep state:
Agree completely that a new battery on a modern laptop will sleep[ for many days if not a couple weeks. But …
Many of us experience reduced life on older batteries. E.g. batteries that used to have a 4 hour capacity now run the laptop for just 30 minutes. This is particularly prevalent on laptops that are mostly used as desktops and seldom unplugged. With such a battery the user could expect a similar reduction in sleep duration as well.
I carried around my old Thinkpad in sleep mode for about six years and never had the slightest problem with the hard disk .The hard disk shuts down in sleep mode. Every laptop is designed to be carried around in sleep mode.
I don’t use Hybrid Sleep (I value the fast-to-sleep nature of the normal sleep settings), but I do have a setting where my laptop will convert sleep to hibernate after 180 minutes if it’s running on battery. I assume this means it wakes up enough to persist anything in memory to the hard disk, which does create some small risk of hard disk damage if it’s jarred while it’s writing.
That said, modern laptop hard disks are pretty good about detecting motion, and protecting themselves. Walking around with a running laptop is a pretty common course of action in a lot of environments. I think backing up important data (or keeping it in cloud storage) and not worrying otherwise is the best course of action.
I’ve traveled across several countries, continents, and oceans with my laptop in sleep mode and never had any problems. I almost never actually turn the thing off.
Question – is it somehow bad to shut your laptop down? Because I really don’t leave mine on when I’m not using it. (And I generally don’t use it on battery, either)
There is nothing inherently bad about shutting down a laptop. The main issue is that you have to wait longer to use it when it was shut down instead of put into sleep mode.
And I generally like to leave a bunch of apps open and have their state persist for many days. If you don’t mind the booting delays and restarting everything you use when you start your computer, no, there’s no harm in shutting down.