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Difference between Fn+F4 and Fn+F12
Posted: Wed Oct 04, 2006 10:00 am
by Dead1nside
Out of curiosity, and to my knowledge I haven't messed around with those keybindings... but what is the difference between Fn+ F4 and Fn+F12...?
On my system at least they both Hibernate it... the little pictures on the keys don't really help me much either.
Re: Difference between Fn+F4 and Fn+F12
Posted: Wed Oct 04, 2006 12:05 pm
by JHEM
Dead1nside wrote:Out of curiosity, and to my knowledge I haven't messed around with those keybindings... but what is the difference between Fn+ F4 and Fn+F12...?
They should Suspend and Hibernate respectively.
Check your power settings if they've changed.
James
Posted: Wed Oct 04, 2006 12:06 pm
by rkawakami
Normally (it least in my experience with 600X and T2x systems), the Fn+F4 keypress puts the system into "Standby" mode and the Fn+F12 option invokes "Hibernation". In Standy, power is still provided to the CPU and memory system, albeit at a lower consumption level. You can "wake-up" the system in an instant by pressing the Fn key down for about 1/2 second. In Hibernation, the current contents of memory is written into a special disk file and the laptop completely shuts down. Upon the next power-up (using the power button/switch), the operating system and all active programs that were running in memory are read off the disk and you basically return to where you left off. These modes can be controlled/selected/enabled/disabled at both the BIOS and operating system levels. Check your BIOS setup and then the OS settings (Power Option Properties/Advanced tab in Windows XP).
The F4 key should show a "quarter moon" symbol. That indicates "sleep". THe F12 key should have a "cylinder" icon on the right. That traditionally means a disk drive (formally called a disk "drum" in the old days).
(edit: Da**! Gotta learn to type faster than James!)
Posted: Wed Nov 01, 2006 11:44 am
by stef-n
OK, excuse a newbie to laptops here.

Are there any disadvantages to using hibernation instead of totally shutting off the computer let's say overnight? Right now I'm having some kind of trouble with my thinkpad whick makes the bootup take forever, or at least several minutes. That is, after windows have started I can usually start any program but after just a short while something makes the processor work a lot (around 50%, I don't know if that means one of the cores works fully, and because I have just one 1x1 gig RAM it is the same as 100% on a single-core machine?) and I can't really do anything for a few minutes but move the mouse around a little. Then it goes back to normal and everything works fine. I guess maybe I should post the second question in some other part of the forum?
Posted: Wed Nov 01, 2006 11:58 am
by dsigma6
stef-n: Use the search feature at the top of the page. This has been discussed in detail, many times. Use standby when you'll be away for a short while, two hours for me. I hibernate when I'll be away from it longer than a couple hours, and always hibernate overnight. The startup time between regular startup and hibernate is like day and night.
Posted: Wed Nov 01, 2006 1:19 pm
by Utwig
I think hibernating before putting laptop in a bag to take it away is also a good idea as on standby it may wake up, this can cause overheating and if HDD spins, well you don't want to bump a spinning disk.
Otherwise it's better to hibernate than to shutdown, although with older models they might get confused if you change hardware (unplug, replug cards, USB peripherals), as it takes significantly less.
It's OK to give your system a reboot now and then. For instance my desktop which is on 24/7 gets rebooted once every couple of weeks or so. I reboot the server every few months or so.
Posted: Wed Nov 01, 2006 2:27 pm
by christopher_wolf
Standby (Fn+F4) puts the system into a sleep state where the contents of RAM are preserved and, therefore, require battery power. The upside to this is that it is almost always quicker to suspend/resume than Hibernation. For Hibernate (Fn+F12), it writes out the data in memory, in a contiguous and compressed sequence, to the HDD and this takes awhile, but doesn't require constant power.
With suspend on modern Thinkpads, you now have the RediSafe feature, which can be enabled/disabled in the BIOS, in the event that the system loses power or runs out of charge on battery. The information in RAM will also be redundantly written to the HDD as well.
There are processes and settings in Windows that can bring the computer out of *both* sleep states, S3 and S4; so one isn't more resilient to being awaked than the other.
HTH
