Far Cry 64
AnandTech: Far Cry AMD64 Edition - A First Look at 64-bit Gaming. _Despite the name, this 64-bit port runs on either Intel or AMD 64-bit chips._
bq. First, we see that the difference between running the 32-bit binary in XP Professional and x64 Edition is basically nothing. Next, there's a modest performance gain seen by the Athlon 64 X2 when using the 64-bit binary - we see a boost of 4%. Note that this sort of a performance improvement isn't noticeable at all to the end user, but there is a numerical advantage.
Interestingly enough, Intel actually does a little better - showing a 6.5% increase in performance. It's tough to say exactly why Intel gets more of a performance boost here, other than assuming that for whatever reason, Intel is facing more register pressure in our particular benchmark.
We're just happy that there is any sort of performance improvement at all - but to those looking for major increases in performance by moving to 64-bits, it's less and less likely to happen.