For those curious about the performance advantages of using 64-bit Ubuntu Linux over 32-bit Ubuntu on a modern Intel laptop, here are 32-bit vs. 64-bit benchmarks of Ubuntu 14.04 LTS on the ASUS Zenbook Prime.
Going back years we have run 32-bit vs. 64-bit Linux benchmarks. While the results seldom change, we keep running them as the question of choosing between a 32-bit and 64-bit Linux distribution image is still a popular question... These tests drive in a surprising amount of traffic and I continue to be flabbergasted by the number of people still asking this question when nearly all modern x86 Intel/AMD hardware fully supports x86_64 and it generally means much better performance. Usually the only caveat in not using a 64-bit Linux image is if running a system with less than 2GB of RAM.