Given yesterday's story about Ubuntu 16.04 LTS potentially being the last 32-bit release if that proposal goes through, and given the number of people still running 32-bit Linux distributions on Intel/AMD hardware that is 64-bit capable, here's some fresh x86 vs. x86_64 benchmarks using Ubuntu 14.10.
Using Ubuntu 14.10 with the latest daily development ISOs today -- just ahead of this week's official Utopic Unicorn debut -- I did clean installs of both x86 and x86_64 flavors and carried out the same benchmarks with the same settings. Using the open-source Phoronix Test Suite automated benchmark framework made all testing easy and effortless.
The hardware used for benchmarking in this article was the CompuLab Intense-PC2 that features an Intel Core i7 4600U Haswell processor. The Core i7 4600U is a dual-core, low-power (15 Watt) processor that is clocked at 2.1GHz with a 3.3GHz Turbo Frequency.
This testing done via the Phoronix Test Suite and OpenBenchmarking.org is quite straightforward to compare Ubuntu 14.10 32-bit vs. 64-bit so let's jump straight to the results.