Today I was doing some web design, and noticed that IE was really slow at rendering the CSS tabs I had for navigation at the top of the page. It was just a simple CSS hover, to change the text and background color when the mouse is over each tab:
#navRow2 a:hover {
background-color: #ecffff;
color: #000066;
}
I popped open the windows task manager, and did some unscientific testing. When I moved my mouse back and forth over the tabs, Firefox used 15-25% of my CPU while IE used 90-100%! That’s a pretty extreme jump. I don’t know why it should take so much CPU to render a CSS hover color change, but it doesn’t surprise me that once again Firefox appears to kick IE’s fanny.