Q: HD 4000 Problems

Problem:

My MacBook Pro started showing graphic issues. For a little bit more than two years the system was running without any major issues, but now it is almost unusable. Last month a few of those hiccups started to occur, but in the last few days they happen more frequently (today over 50 times).

The graphic issues manifest in stuttering user interface, which usually means that the monitor freezes and temporarily becomes unresponsive. Sometimes the a second occurring freeze after 10 sec results in an application crash, sometimes the applications run a little bit longer. Sometimes the stutters throw me back to the log-in screen or restart the computer.

This behavior occurs in applications such as Safari, Preview, QuickTime, VLC and Heroes of the Storm. It's also impossible to play videos.

What I already tried:

The extended Apple Diagnostics tool didn't show any errors. I've reset PRAM and SMC. I also reinstalled the Combo Update 10.10.4 and I even reinstalled the OS from the Recovery Utility. The error persists. I have attached the beginning of one of the console logs which is related to the freezes.

Any other ideas on what I can try?

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System Details:

MacBook Pro (Retina, 13-inch, Early 2013)

OS X 10.10.4

Intel Core i5 2,6 Ghz

8 GB RAM

Intel HD Graphics 4000

Console Log:

Event:               GPU Reset

Data/Time:           Sun Jul  5 18:23:08 2015

Application:         com.apple.WebKit

Path:               

OS Version:          Mac OS X Version 10.10.4 (Build 14E46)

Graphics Hardware:   Intel HD Graphics 4000

Signature:           8013

Report Data:

===========================================================================

                         Intel GPU Hang Summary

                              version 1.0.0

===========================================================================

-- Summary of Status for ALL Rings --

MAIN Ring is hung in a batch buffer <-- ROOT CAUSE!

MEDIA Ring is idle

BLT Ring is waiting on a semaphore

[.....]