Mac OS X 10.10.4: Artifacts (Pixel Junk) when dragging a window on secondary screen on 4K display

Originator:winsmith
Number:rdar://21919356 Date Originated:21/6/15
Status:Closed Resolved:20/8/15
Product:OS X Product Version:10.10.4
Classification:UI/Usability Reproducible:Always
 
Summary:
When a Samsung U28D590 4K Display is attached to the Retina iMac in , dragging any window will result in serious graphics corruption inside the dragged window’s frame. The corruption will only go away when the window redraws.

Steps to Reproduce:
1. Obtain an iMac15,1 with Intel Core i7 and AMD Radeon R9 M295X
2. Attach a Samsung U28D590 4K Display to the iMac using a standard MiniDisplayPort to DisplayPort cable
3. Set the display to extend the screen
4. Set the Resolution to be “Scaled, looks like 2560x1440”
5. Drag any window into the screen, and/or drag one around inside it.

Expected Results:
The window will drag around smoothly.

Actual Results:
The window frame is filled with vertical and horizontal stripes, mostly in the colours of the desktop background image.

Regression:
The problem does not occur in native scaling mode. It does occur in “Looks like 2560x1440” scaling mode, and it does occur in any other scaled mode as well.

Notes:
n/a

Comments


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