The PC Gaming Wiki, "Skyrim" article states that "Disabling V-sync is HIGHLY UNRECOMMENDED. It introduces bugs with physics, time-scaling, graphics and controls", with this Bethesda forums post, "Do NOT disable vSync!" as its source:
The number one "fix" on this forum for Skyrim is to disable vSync
through the "iPresentInterval = 0" tweak in the INI file. However over
the last week or so it's come to many people's attention that
disabling vSync this way causes all manner of bugs and glitches.
Notice that even if you force vSync through your GPU's control panel,
Radeon Pro, DXD3Overrider etc, these bugs will still persist. The only
way to stop them, unless noted otherwise, is to set iPresentInterval
to 1.
Crazy Physics
Allowing your FPS to go over 60fps causes the physics
engine to go a bit out of control. The slightest touch, even opening a
door, can send pots and pans 10 foot away flying all over the place.
Whilst this may seem funny, it can have disastrous consequences if a
really important item flies so fast it gltches out of the playable
area.
This can however be solved by limiting your FPS to 60.
Day and time out of sync
With iPresentInterval disabled, the time and
day will gradually go out of sync. Shadows update correctly, shops
close and open at the right time and the sun sets and rises correctly.
However the physical day (for example Turdas) won't change until 5pm.
This not only breaks immersion, but can also break some quests where
the AI relies on the actual day changing.
NOTE: It has been confirmed that this will cause NPC schedules to go
out of sync, and does break some quests.
This cannot be fixed with a FPS clamp, or by forcing vSync
externally.
(there are also other issues with disabling Vsync mentioned in that forum post)
So, the solution is to enable Vsync internally:
- Go to
%USERPROFILE%\My Documents\My Games\Skyrim\
- Open
SkyrimPrefs.ini. Navigate to the [Display] section.
- Set the entry
iPresentInterval=0 to iPresentInterval=1
- Save the file.