I wanted to learn how to dynamically update the favicon using the Google Chrome browser and I've noticed that the browser seems to throttle how often you can update the favicon per second and that sort of makes things look sloppy. The test page I've made for this is:

http://staticadmin.com/countdown.html

Which is simply a scrolling message displaying the results of a countdown. I added an input field to tweak how many pixels per second are moved by the script and I've eyeballed the max to be about 5 frames per second smoothly in Google Chrome and I have not tested it in any other browsers.

My question is what is the maximum frequency, are there any ways to change, is there a particular reason behind it?

NOTE: I've also noticed that this value changes based on window focus as well. It seems to drop to about 1 update per second when the browser's window isn't in focus and returns to "max" when you return.