An increasingly popular option for "switchers" from Windows XP to OS X or Linux is to run XP in a virtual environment instead of giving it up entirely. My feeling on that is that it’s the best possible maneuver you can do because you don’t lose anything save for game and performance and video-intensive apps.

There are those that say "make the leap" and completely abandon Windows altogether, but in reality that’s just not smart. You should wean yourself off Windows instead of just forcing yourself into a situation that requires you to re-learn everything all over again.

In addition, you may have licensed software that’s Windows-only, so setting up a virtual XP saves you cash so you don’t have to re-buy (if it’s even available) certain Windows specific apps.

64-bit CPUs have been around for a really long time (since the 1960s believe it or not) but the vast majority of computer users today are still using 32-bit CPUs.

All new Mac Pros have 64-bit, but those that opt to go the Linux route mostly run 32-bit systems currently. This is because they already have a box, so why bother getting new gear when *nix will run on it just fine?

It’s not an issue of whether or not Linux will run on the box. It’s an issue of how much memory you can utilize.

A processor with 32-bit memory addresses can directly access 4 GiB of byte-addressable memory. That’s it. That’s the highest you can go.

As a side note, Windows XP can technically only address 3GB of RAM due to a by-design OS limitation. What this means is that anything over 2GB of RAM in Windows XP 32-bit is essentially overkill. So if you were thinking of filling those extra RAM slots on your motherboard above 2GB, don’t bother if the OS is XP.

Linux on the other hand can recognize a full 4GB in a 32-bit setup (as far as I’m aware), but you can’t go any higher due to 32-bit limitations.

64-bit systems can handle much more than 4GB of RAM.

The Big Question: Why would anyone need more than 4?

If you plan on running Linux and "virtualizing" XP, having more than 4 would help out a great deal.

Let’s say for the moment you had 8GB of RAM on-board. This means you could assign a full physical 2GB to VMWare or Virtualbox for your virtual XP and have 6GB left over for native Linux stuff.

Assigning memory in this fashion allows everything to run smooth as silk. XP will be at its optimum running speed with 2GB of RAM and whatever Linux you choose will blaze along with 6GB at its disposal. Being that many distros have native 64-bit editions you get to harness the full power of not only the 64-bit CPU but also memory that couldn’t be addressed with a 32-bit system.

When you come to the point where you’re ready to ditch XP – if that’s your goal – you can do it at your own pace on a system that can run both OSes at the same time quickly and efficiently. Or alternatively you can keep your virtual XP indefinitely if there are things in there that just aren’t available in Linux for whatever reason.

Furthermore you have a setup that, said honestly, can be used and stay relatively modern for a good 5 years. You will have your XP for your legacy apps and Linux for everything else.

Reality-Check notes

Building a 64-bit box just to run Linux and a virtual XP takes a serious level of commitment. You have decided that yes, you want to use something different that won’t break the bank. Linux is free and building a 64-bit box is far cheaper than buying a Mac Pro.

However you have to really like Linux (and really hate Windows) to do this. Your newly-built 64-bit box won’t run optimally with XP as its OS if you decide to switch back. Once you go forward you cannot go back else you will have wasted cash on the box you just built.

Eventually it’s going to come to the point where all new computers are 64-bit and beyond. The 32-bit architecture at this point works but is seriously showing its age.

Windows XP is a fantastic operating system due to the fact it has more support than any other OS, but it’s old. Service Pack 3 is the last hurrah and then it’s all dust in the wind after that point.

At the present time the only two modern OSes that have the future in mind are OS X and Linux. Both have 64-bit capability. Both can run XP virtually for legacy Windows applications (and the stuff you paid for previously).

Your choice is whether you want to spend $2300 for a Mac Pro (and just a scant few extra bucks for virtualization software) or spend sub-$1000 for a PC build for Linux (with free virtualization software).

If you’re of the mindset that XP is old hat and ready to make a jump but weren’t exactly sure how to go about it, having a 64-bit box with virtual XP for legacy stuff is your best bet. It does take effort; it does take time; it will cost you money.

But it’s the least shock to your system (as in yourself) that will allow you to gradually adjust to a different operating system and a different way of computing.