# Mouse Movement causing Flash Player slowdown

**URL:** <https://forum.kirupa.com/t/mouse-movement-causing-flash-player-slowdown/297417>\
**Category:** flash\
**Created:** [October 1, 2009, 6:21pm UTC](https://forum.kirupa.com/t/mouse-movement-causing-flash-player-slowdown/297417 "2009-10-01T18:21:44Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Cybexx](https://avatars.discourse-cdn.com/v4/letter/c/d26b3c/32.png) [@Cybexx](https://forum.kirupa.com/u/Cybexx)\
**Post date:** [October 1, 2009, 6:21pm UTC](https://forum.kirupa.com/t/mouse-movement-causing-flash-player-slowdown/297417/1 "2009-10-01T18:21:44Z")

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I am struggling with an issue at the moment related to mouse events or more specifically mouse movement. I have found that moving the mouse in my game causes it to slow down. Rapidly moving the mouse can actually freeze the game, I believe EnterFrame events are actually dropped when the mouse is moving rapidly.

I thought at first that it must be something I coded incorrectly so I used the Flex 4 Beta’s performance tools and analyzed the Flash 10 SWF that I build using Flash CS4. Mouse Events were the leading performance hog by far.

Whenever the mouse moved the CPU usage would skyrocket. I then tried an empty Flash App with no Actionscript, I had the same CPU spike.

So if I’m getting this problem with a Blank SWF how come I don’t see this problem talked about all over the internet, how is every other Flash Developer not running into this problem?