Originally Posted by plonoma
Honestly, x86_64 is one of the most overrated things in browsers. Yes, it can give a very small performance boost, increase the ram usage limit (anyone will complain if a browser uses more than 20mb of ram with 100 tabs open anyway) and gives better ASLR, but there are many things that could improve everything more and require less efforts (Windows is awful when it comes to 64bit).
~ zypper if MozillaFirefox | grep Arch
Also, given that this is a Linux site, the 64bit problem is solved already, as Firefox is 64bit on that.