Here's a little of what it says in the BIOS power managent section of a M/B manual I have handy. bear in mind this is an old board.Which makes me wonder, what _Exactly_ does suspend do
The system consumption is reduced according to the following sequence"
Normal > Doze > Standby > Suspend. Each mode can have its own timer set for its events rangeing from 1 minute to 1 hour.
events can be assignemd to each stage or stages can be skipped deopending on user sonfiguration.
for instance. You could park the HDD if its not used in say 5 minutes (Doze) then turn of the monitor after another 10 minutes (Standby) and finaly throttle down the CPU by 12.5%-75% (suspend).
you can also set wake up events as well Like wake on LAN, wake on COM2 (you can dial up with a modem and remotely start your machine), etc. the most common are wake on mouse (com1 or USB) and wake on keyboard.
When power managment first became a big thing people used to turn everything on (to save the most power) but didn't set any wake on, commands. So their machines would go into a coma and have to be cold booted to wake em up. This was very common with laptops.
If your really interested in power management info you might want to read your M/B manual regarding your BIOS settings.