Putting your PC to rest: Which one is for you?

Putting your PC to rest: Which one is for you?

"Shut Down" closes down all applications, the OS, and powers off the whole computer*. When you restart, you go through the BIOS startup, and then boot the OS to an empty desktop.

"Hibernate" writes the current state of the OS and open applications to a disk file. This takes several seconds. It then powers off the whole computer (like Shut Down does). When you restart, the computer goes through the BIOS startup but then, rather than booting the OS in the normal way the operating state is reloaded from disk, which again takes several seconds. You are then presented with your applications open, just as you left them.

"Standby" shuts down most of the computer (hard disks, processor, fans, screen), but leaves the memory powered up, along with some of the peripherals. It's rather like "freezing" your computer at a moment in time. It is quick: it doesn't require the current state to be written to disk. Resuming from standby is also quick: effectively it just "unfreezes" the processor and carries on from where it left off. It has one major
disadvantage: if the power is removed whilst the computer is in standby, the operating state of the OS and applications is lost. This can lead to data loss.

"Sleep" is a new mode introduced with Vista, and it's a clever combination of Standby and Hibernate. "Sleep" writes the current state of the OS and open applications to a disk file - just like Hibernate - which takes several seconds. But then it effectively puts the computer into standby - that is, it shuts down most of the hardware but leaves the memory powered up. Provided the power remains on the computer whilst it is "Sleeping", it can resume almost instantly, because the operating state is preserved in memory and it just "unfreezes" the processor, like resuming from the old Standby. If the power should be lost whilst the computer is in Sleep, no data is lost because the operating state was saved to disk. In this case the computer goes through the BIOS startup and then reloads the operating state from the disk file, just like coming out of Hibernate.

"Sleep" is wonderful: it allows an almost instantaneous resumption to your open applications if the power was not interrupted. If it *was* interrupted, it still resumes to your open applications, but it takes a little longer.

The supposed effects of starting and stopping your hard disk, as opposed to running it 24/7, are NOT well established, despite what a few opinionated but ill-informed hot-heads in this newsgroup will tell you. There is no *conclusive* data to suggest which is better for disk life (you might like to look at the research Google have done in this field), or the life of the other electronics.

Powering down your computer will definitely save energy, though. The best way to power it down by far is the new "Sleep" mode in Vista, which is the default function of the "power button" icon you can see when you click the Orb. It allows an instant resume if the power was uninterrupted whilst the computer was "sleeping", and a pretty quick resume if the power was removed for some reason. I recommend it.