[stakanov]

LOL, this depends on the type of processor and of the RAM.

Although this seems to be in contrast with the prior posting of our colleague:

you have to distinguish to problems when deciding over 32 or 64 bit version. The "feasibility" and the "sense".

It is often more a problem of "sense" then of technical feasibility.

Nearly all modern processors are 64 bit. Intel processors Core2Duo are to my knowledge all 64 bit ready.

Therefore it is "feasible" to install the system 64 bit. You where right however to ask about the RAM. The RAM of your system will influence the decision about the fact if what is "feasible" would also be "sensed".
To make it short:
if your system has below 2 GB of RAM it is useful (in my experience) to stick to 32 bit.
The system otherwise risk to be sluggish and to appear overloaded, especially when you have below 2 GB. Technically nearly the same software for 64 and 32 bit are now available and the quality of both is equivalent.

If your system has 3 GB I personally would advise 64 bit already because I feel the machines I installed run somehow more "solid" if a lot of applications are running parallel on that kind of machine. But it may be a "subjective bias".

When does it come to "sensed" is in the moment you run a system with more than 4 GB. In this case the 32 bit system cannot address physically the RAM available. A normal kernel 32 bit would therefor "see" only 3 GB for programs and 1 GB for the system even if you have 6 GB installed.

Linux did overcome partially the limitation with the PAE kernel (with which it is able to address more then the usual 4 GB max) but after the 4 GB it is advisable to switch to 64 bit, also because there is more and more software available that makes full use of multiprocessing and available RAM.

You will want to use 64 bit, particularly if you run VirtualBox or if you do Video editing and Photo editing. The bigger the files you are using the more advantage you get out of your 64 bit system.

Another software with which you will want to employ a system with 64 for bit is statistical software, especially if "monoliticaly" programmed. STATA would be such a software. IF you owe proudly a multiprocessor, 64 bit version STATA your own, you will be able to take full advantage of 64 bit either in terms of speed as in terms of available RAM for statistical calculations to be attributed, without making the system instable.