…and the world strarted to turn to 64 bits OSs.
The popular argument is that a 64bit operating system could address more memory than the ~3.5GB 32bit OSs stop at.
However, with Linux, this is no argument as the bigmem patch (now called PAE) can address as much memory as you can throw at it, so why bother with using 64bits when some applications (still!) struggle to deliver native 64 apps?
Here’s a recent performance test showing the performance of 32bit with ~3.5GB, allocated 32bit with the bigmem patch and ~4GB RAM and a 64bit kernel also with the same amount of memory. In some areas there’s not much difference, whereas in most there are big performance benefits.
So the big question: why should someone use 64 bit? The real reason is that a number of vital operations on the computer are significantly faster than their 32bit counterparts
http://www.phoronix.com/scan.php?page=article&item=ubuntu_1204_3264&num=1