Hmmm,

In the past I used to think that FireFox was badly designed because it appeared to leak memory like a sieve. Now I suspect that this is intentional, presumably to make it appear quicker?

Right now FF is taking up 700MB of RAM on this new laptop, but it has 8GB of DDR3/1333 so that doesn't matter.

For the past few weeks I have been using an Asus eeePC netbook as both my production machines died on the same day

SPECIFICATIONS:

Intel Atom N570 1.67GHz dual core with hyperthreading.
1GB DDR2
5400rpm HDD
4GB SD card running ReadyBoost
Windows 7 Starter
2GB pagefile

After about 30~45 minutes the thing will slow to a crawl or worse with 95+% RAM and 50% pagefile usage, and the culprit is FF.

I installed some FF addons that seem to have reduced the problem, but make FF run much slower and pause the machine every now and then whilst they retune FF.

I shall have to look at alternatives.......FF is now up to 720MB and all I have been doing is typing this!