This is a test conducted on Windows XP 64 bit edition.
Browsers tested
- Internet Explorer 7
- Opera 9.21
- FireFox 2.0.0.5
- Safari 3.02 for Windows
The test
You need a mouse with scroll wheel to do fast scrolling.
Open each browser and load http://www.jamespaulp.us/.
Open Windows Task Manager. Switch to Processes tab. Make sure Image Name and CPU columns are listed. If not go to the menu View->Select Columns and select CPU Usage column. Click on CPU column header to sort it by CPU Usage. Make sure you are at the top the list by clicking the home button. Keep the task manager window always on top.
Now switch to one browser at a time and start scrolling up and down in quick successions. Just move your finger up and down on the scroll wheel. Watch the CPU usage.
The Result
With Internet Explorer and Opera, you can see the CPU usage climbing above 50% very quickly.
Both FireFox and Safari remains below 10% level all the time.