Bug 385206

Summary: Resizing windows is very laggy
Product: [Plasma] kwin Reporter: Buck Shockley <darkwingbuck13>
Component: coreAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED NOT A BUG    
Severity: normal    
Priority: NOR    
Version First Reported In: 5.10.5   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Buck Shockley 2017-09-29 14:40:52 UTC 
If I resize a window without enabling the Resize Window effect in Desktop Effects, the resizing effect is very jerky and laggy, but if I DO enable it (so that windows are resized with a texture instead of in real time), the resizing effect is smooth.

Running Nvidia 375.82.
Comment 1 Martin Flöser 2017-09-29 17:35:20 UTC 
The speed of resizing depends on many factors:
 * does the application support the sync protocol
 * is the application able to re-render in the needed size at all
 * which GPU/driver is used
 * overall load of the system

In general resizing of windows is synced in KWin. That means we wait for the application to repaint and will only start the next resize step if the window keeps up with the sync. This means the main factor is the speed of the application. KWin has no influence on this.

As we know that there are setups where a smooth resize is not possible we have the resize effect to support non-resizing setups.