What wears out in an HDD. Hybrid sleep

Giganews Newsgroups
Subject: What wears out in an HDD. Hybrid sleep
Posted by:  micky (NONONOmisc…@bigfoot.com)
Date: Mon, 04 Jan 2016

For a friend with Win7.

IIRC in Vista and 7, the default for a hard drive turning off was
never.  Never?  Even for people who leave their computer on 24/7?
Doesn't it extend the life of the harddrive to turn it off when not in
use?  Or is it only the tone arm that breaks and the bearings the
platter rides on never break???  What wears out in an HDD?

When I was visiting him, I tried to set up his power options for him
but at the time I'd never heard of Hybrid Sleep.  I only had 30
minutes so I went home instead!    Wikip says "Sleep mode and
hibernation can be combined: The contents of RAM are copied to the
non-volatile storage and the computer enters sleep mode. This approach
combines the benefits of sleep mode and hibernation: "  But what I
read elsehwere was that the *data* areas of RAM were copied to the HDD
and it didnt' say how it knew where the data was kept.  My aunt Tillie
would hide data all over the house, in the cookie jar, the sofa
cushions, etc.  How do I know Hybrid Sleep finds all the data if it it
only tries to copy data??

If one were to use plain old sleep on some computer, what data could
be lost in a power failure?  Is it only the most recent changes to a
file one is working on in a file composition window, like an email? Or
are there hidden non-easily recreatable files that also need to be

For example, if I change preferences and settings in most programs,
they are saved during full Hibernate or full Shutdown, but not at all
in simple sleep.  Are they saved in hybrid sleep?

Also, full shutdown and full Hibernate obviate the need to run chkdsk
in case of a power failure.  If there is a power failure during hybrid
sleep, woudl chkdsk run on restart?  (Lets assume the user is away
from his desk so long that the UPS runs out of steam.)

Thanks a lot