I then closed and reopened firefox on both systems, and opened the six original tabs plus this debug page. Memory usage is now 171.9 MB, much closer to the XP figure which is now 142MB after reopening.
I then closed and reopened firefox on both systems, and opened the six original tabs plus this debug page. Memory usage is now 171.9 MB, much closer to the XP figure which is now 142MB after reopening.