On Wednesday 17 December 2008, Arjan van de Ven wrote:
On Tue, 16 Dec 2008 17:16:36 -0500 (EST)
Seth Vidal <skvidal(a)fedoraproject.org> wrote:
> > Or hibernate?
>
> At least on my system hibernate takes as much time as a reboot.
btw this is a very fundamental property of hibernate. You need to do all
disk IO to get the system state to disk. And then at resume, you need
to do all disk IO to get the state from disk again. That's twice ;)
This is compounded by the property that a hibernate tends to flush at
least half the disk cache (it has to, to get space to work in), which
you then need to page right back in, so even when you're back, the first
minute or two sucks badly.
I suspect you will always be able to boot faster than you can
hibernate+resume.
I have very different experience. For example comparable (from grub going
away to KDE + my bunch of default apps running and usable) numbers just taken
from the desktop box in front of which I'm right now (AMD64 3200, 2G RAM,
SATA, F-9 x86_64 KDE):
- shutdown: 28 sec
- fresh boot: 66 sec
- suspend to disk: 17 sec
- resume from disk: 23 sec
Shutdown takes a ~5 second penalty compared to suspend to disk due to the
shutdown sound during which everything else appears to be idling, and fresh
boot takes a bit of a penalty because my most recent readahead-collector run
(using the F-10 one) is not very recent, but the numbers speak for themselves
anyway. Also, I have a gut feeling that the sluggishness for a while after
the desktop is up is clearly worse on a fresh reboot than in resume from disk
case. But it's possible that I misremember this one - I haven't really shut
down/rebooted except for kernel updates in almost half a year.