A common question that pops up from time to time is whether someone who has a 64-bit CPU (such as an AMD64 or an Intel EM64T) should install a 64-bit or 32-bit version of the preferred OS. Since these processors are capable of running either one at full native speeds, what are the advantages and disadvantages to both? 64-bit just sounds cool and faster, but we all heard about headaches installing the OS, drivers and software. Are they still valid or a thing of the past?

Compatibility – Not all software runs on 64-bit Linux. Although there have been 64-bit native Linux distributions for several years, the software community has yet to fully embrace the technology. Not all hardware has 64-bit drivers yet. The two major display card manufacturers (ATI and Nvidia) do have X86_64 versions of their drivers, but they are sadly the exception rather than the norm.

Speed – Without a scientific set of benchmarks this one is really hard to measure. Some people think one distribution “feels” faster than another while others disagree. Suffice to say that no one has yet to prove scientifically that the 64-bit versions of Linux available today are significantly faster in performance than their 32-bit counterparts. Most 64-bit versions of software are actually just recompiled versions of the 32-bit code, with no optimisation that would take advantage of the new features these chips offer and perhaps boost performance. If you’re looking to use 64-bit because you think it will be a major improvement in speed, I would reconsider.

RAM – If you plan on using a machine that has more than 4GB of RAM, you’ll need to use the 64-bit version of your distribution because 32-bit operating systems are only able to handle up to 4GB, maximum. There’s just not enough memory addresses for more. With RAM becoming less expensive by the day, the 4GB limit is not really applicable for most users any more.

Being “Cool” – As Apple Computer has proven in recent years, there’s an awful lot people will do just because something looks or feels “cool”. This is perhaps the one reason why some people choose to run 64-bit Linux: it’s a neat idea. To some people the idea of running a 64-bit native operating system on their 64-bit CPU is just too cool to pass up. These people understand the drawbacks to running a bleeding-edge system and accept the extra work involved. If this describes you, more power to you.

Which one is it? If you’re a geek or at least have an in depth knowledge about compiling and installing software, have no issue editing configuration files and/or need more than 4GB of RAM, go for it. For the rest of us, it’s just fun to download the latest offerings from you preferred distro, install it and give it a test ride. With every release, there are more software included, 64-bit drivers that work and an OS that’s more stable and faster than its predecessor. You might just like it and decide to keep it.