Windows don't refresh correctly on external display

Number:rdar://19381639 Date Originated:1/5/2015
Status:Duplicate/19237518 Resolved:
Product:OS X Product Version:10.10.1
Classification:UI/Usability Reproducible:Sometimes
After a period of time, windows on an external display do not refresh correctly.

The behavior occurs consistently on a Retina iMac using either a Dell 30" monitor with a Dual-link DVI adaptor or an Apple Thunderbolt Display.

Steps to Reproduce:
1. Use your Mac for a day or two.
2. Move a window around on the external display.

Expected Results:
The window should not "sparkle".

Actual Results:
The window on the external display (non-Retina) "sparkles".

Here is a movie of it in action:

10.10.1 (14B25)

This behavior does not occur when you try to do a screen recording using QuickTime Player.


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