Major suspend changes

Major suspend changes

Suspend-to-RAM simply puts your hardware in a low-power state, using ACPI or whatever mechanism ppc machines use. It's fairly fast, but the machine will continue using (a little) power when suspended. The major downside is that in Linux, it's horrendously unreliable: there is a very good chance of your machine unsuspending to an unresponsive state, and since modern machines typically lack a serial port (for attaching a serial console), your only choice then is to reboot and lose data.

Suspend-to-disk writes your memory to your disc (typically, in a compressed form to your swap partition), then powers down. When you boot the machine back up, you pass the kernel a parameter where to look for the suspend image; if it finds it, early in the boot process it will load the image back into memory. This is slower than suspend-to-ram, but doesn't use any power when suspended, and most importantly, WORKS. I.e. Suspend2, when properly configured, reliably works on pretty much any hardware I throw at it. Suspend-to-ram doesn't. Hopefully, Linus's patch will change the situation.