You can run 32 bit binaries on 64 bit system. I bet Ubuntu has several 32 bit packages available because they are needed by Wine and and closed-source 32 bit binaries.<p>The theoretical possibility for speedup is exactly why I asked. The x32 website has benchmarks where it&#x27;s as fast as i386 and 40% faster than amd64 on pointers or as fast as amd64 and 40% faster than i386 on 64 bit math, but what&#x27;s missing to really justify x32 is some &quot;20% better than either&quot; case.