Created attachment 245781 [details] CPU Profile of 12 image demo I apologize in advance for not being able to determine the exact issue here, or provide a reduced test case. Overview: Essentially, this is was found while using the jQuery AnythingZoomer plugin. There is a significant delay (2-3 seconds) that is introduced when trying to position a div containing more than 10 stacked images under the cursor; with 10 or less images the behavior is as expected. This issue does not occur in Firefox, Opera or IE11 (I didn't test in older IE versions). Here is a demo of the plugin behaving as expected (10 images in large container): http://jsfiddle.net/5j354atc/3/ Here is a demo of the huge delay (12 images in large container): http://jsfiddle.net/5j354atc/2/ Steps to Reproduce: 1) Load the demo; there is an expected initialization delay of a second or two. 2) Move the mouse anywhere over the map. 3) Notice how long it takes for the zoom window to appear under the mouse. Actual Results: In the 12 image demo, I ran and profile and examined the flame graph (CPU profile attached). I noticed that jQuery was not receiving any mousemove events
Continued... Expected Results: The zoom window moves with the mouse cursor with minimal delay. Build Date & Platform: Version 40.0.2214.94 m on Windows 8.1 64bit
Sorry, I included the version of Chrome above; it was reported to me that this issue also occurs in Safari, which I don't have access to.
Update: The AnythingZoomer repository was moved under the CSS-Tricks organization, so the previous demos stopped working. Here are links pointing to the updated demos: 8 image demo: http://jsfiddle.net/Mottie/5j354atc/8/ 10 image demo: http://jsfiddle.net/Mottie/5j354atc/6/ 12 image demo: http://jsfiddle.net/Mottie/5j354atc/7/ After updating these demos, it appears that the issue has gotten worse! I now see a big delay with 10 stacked images. This delay disappears (after about 2 seconds of mouse movement) when 8 images are stacked. Again, there is no noticeable delay in Firefox even when using 12 stacked images.
This is no longer an issue... just tested in the latest versions of Chrome & Opera (no Safari on Windows).
Mass move bugs into the DOM component.