The issue occurs for sure on desktop systems. I have an HTPC that shows this issue.
Asus H87i-plus, i7-4770k, intel HD 4600 graphics, Windows 8.1. HDMI cable from motherboard to TV.
I have the same behavior as Keleg, Dennis and Ray have reported.
Kevin- It is important to note the the issue only occurs under 8.1. The exact same driver under 8 does not show the issue.
Kevin- I have tested every Intel graphics driver I could find that supports HD 4600. Every single one of them have this system commit issue when running under windows 8.1. If you have 8.1 installed and you have an HDMI cable from your motherboard directly to your monitor try this test: Start task manager. Open up a Commit Charge vs. time display (Performance tab, Resource Monitor, memory tab). Start up a full screen WoW game (not windowed). Power off your monitor for 15 minutes. Power on your monitor. Alt-tab out of WoW. View Commit Charge graph.
Does it stay nice and level or is there a saw tooth like the one that Ray posted? I would really like to know the answer to that question.