I followed the guide two times and own two models of 8460p, same issue than:
look here
https://forum.videolan.org/viewtopic.php?t=122308
The problem somehow exists under windows 8 too.
Impossible to run VLC flawless on W8 nether.
The problem appears when using a non GFX accelerated app like VLC. On Win8 VLC stacks completely, impossible to watch a movie without lagging.
On MacOS what i noticed is:
-Problems with deep sleep. (Computer restarts if mouse scrolling to fast at login page waking up).
-And OS freezing when using the Mission control windows browsing during Hi Res Movie back playing using a non GPU accelerated app.
No Mac or MS issues anymore if using a GPU accelerated app (like Quicktime or WMP).
Since i removed AppleGraphicsPowerManagement Yosemite runs flawless but my Battery life is in danger
I still want to find a better solution but for sure i installed (three times) my Elitebook and this problems still exists.
Regards.