very high CPU% when downloading files
i checked activity monitor on osx lion 10.7.5 (using the latest firefox, tried the nightlies) and the CPU% goes from about 30% to 110% when downloading files (when they complete, the CPU goes back down again). it seems not to matter what types of files they are, just the fact that they are downloading. i don't see why or how this should happen, as all browsers i have used before recently switching to FF have never had this behavior.
Alla svar (2)
Use the add on 'Down them all"and let it get more than 3 connections to speed up the process, While using Less RAM.
Firefox uses too many CPU resources - How to fix At times, Firefox may require significant CPU resources to display content. We'll show you options for fixing this if this if it is happening too often.