Some of you might have noticed a new option called Allow Hybrid Sleep when configuring some of the advanced power options in Vista:

Hybrid Sleep mode in Vista

You’re first thought was probably "huh?" which is exactly what I was thinking. I did a little research and was able to come up with the differences between this hybrid sleep mode and the normal sleep mode.

–Normal Sleep Mode–

With normal sleep mode a computer will go into standby, which is a state your computer can quickly resume from. It basically keeps power flowing through your memory, but just about everything else is shutdown.

If the computer gets close to running out of power, it will store the contents of your memory onto the hard drive. This is known as hibernation, and the computer doesn’t resume quite as fast from hibernation as from standby, but it can still restore the state of all your applications.

The switch to hibernation is important because otherwise the state of your computer, and anything that wasn’t saved, will be lost. No hibernation would be like your computer crashing without warning.

As you can see the normal sleep mode is great for computers that have a battery, such as a laptop. If the battery starts to get near the critical state it can store everything on your hard drive so that you can still resume where you left off.

–Hybrid Sleep Mode–

But what about desktop computers? If you put your computer into standby, and then a little bit later your power goes out, everything will be lost. The desktop has no time to put the computer into hibernation like a laptop would, so you’re left with nothing.

Well, not with the new hybrid sleep mode. With this enabled your computer will store the contents of your memory immediately when entering sleep mode. That way if the power is lost later on it will still be able to pick up where you left off. If nothing happens, however, the computer will quickly resume from standby just as it normally would in sleep mode.

This isn’t really designed for laptops since they will automatically enter the hibernation state when the battery level turns critical, but for desktops this is a huge help. If you do enable this on a laptop the computer will never officially enter the hibernation state when the battery gets low, because it is already prepared for hibernation when it enters the standby state.

By default this is disabled on the laptop computers because it takes longer to enter the standby state. I guess it might be useful on a laptop if your battery randomly falls out of your computer while carrying it around. :)