Mozilla for Windows x64 platform

If you want the best performance from a piece of software you need to have it compiled to support the features of your CPU. Mozilla Firefox is one such product.

http://www.mozilla-x86-64.com/ is a site which (surprisingly enough) has ports of Firefox built for the AMD64 platform under Windows. Of course, you will need to have a 64bit version of Windows so currently the userbase will be somewhat limited. However, I'm sure quite a few people here are on the beta programme, so this site may be useful to you.

i think 64bit plugins are also somewhat lacking - the same applies under 64bit msie, which has no plugins (and can't use, say, windowsupdate), or under 64bit linux (i use a 32bit firefox, for the plugins)