http://www.reddit.com/r/windows/comments/1oor43/windows_81_warning_for_gamers_issues_with/
http://www.eurogamer.net/articles/2013-10-21-windows-8-1-causing-mouse-lag-that-badly-affects-games
From Mark Cranness (Creator of the Windows 7/8 Mouse Acceleration Fix)
Some users have reported this as a temporary fix, however it's unclear if it applies to all cases:
http://www.eurogamer.net/articles/2013-10-21-windows-8-1-causing-mouse-lag-that-badly-affects-games
From Mark Cranness (Creator of the Windows 7/8 Mouse Acceleration Fix)
I've seen this 8.1 lag in a tool I wrote/modified to record and debug mouse movement.
It is real lag, and as OP said, affects games that don't use Raw Input (or DirectInput, which is more-or-less the same thing) for reading the mouse.
When I first saw this lag in 8.1, I improved the debug detail of the recording tool a lot, to see if that might help explain what was happening. Before the improvements, the recording tool pretty much showed : "WTF? something is strange". The improvements clearly showed lag between mouse movement happening and Windows updating the pointer position.
(Updating the pointer position matters because games that don't use Raw Input or DirectInput to read the mouse usually instead look at how the on-screen mouse pointer moves to decide what the mouse must have done - aka old-style Quake GetCursorPos calls to read mouse movement. If Windows doesn't update the pointer position in a timely manner, the game mouse will lag.)
Seeing that it IS a problem is as far as I've gone so far in diagnosing it.
BTW, the fix above (EXE Properties) doesn't seem to affect my recording tool at all : It still shows lag.
The tool is MouseMovementRecorder.exe, part of the MarkC mouse fix, if you want to experiment, get it from here: The MarkC Windows 8.1 + 8 + 7 Mouse Acceleration Fix MouseMovementRecorder.exe is inside that ZIP file (in an embedded ZIP file).
Some MouseMovementRecorder.exe keyboard key commands that help show the problem: * E : Toggle showing of extra detail. * + : Increase maximum catchup delay. * A : Toggle 'Enhance pointer precision' Acceleration.
If you don't already have the Control Panel > Mouse > 'Enhance pointer precision' checkbox OFF, then press > "A" key until EnPtPr shows Off. If you don't have the Control Panel pointer speed slider set to 6/11 (the middle position), press "6" key. Press "+" key until the displayed Max catchup delay is 8000 or even 64000.
Move the mouse and often you will see pointer movement recorded 2000µs or 5000µs or more after the mouse movement. (Jiggle the mouse when testing : smooth or straight movements might confuse the matchup-process that MouseMovementRecorder uses. Pay attention to blocks where the numbers match; probably ignore blocks that don't match and display red or green.)
Some users have reported this as a temporary fix, however it's unclear if it applies to all cases:
Run the program in compatibility mode for Windows 8.
Disable display scaling on high DPI.
Run this program as an administrator.