Back in the late nineties we experienced a transition from 16-bit to 32-bit computing.  The transition was neither smooth nor particularly drawn out.  Currently we are in another transition – this one from 32-bit to 64-bit computing, and this time the transition will for the near term be much smoother and much slower.  The reality is this transition started a couple years ago, but the reason I’m now writing a post about it is that in my opinion, if you are considering a new PC, the point of transition has been crossed – purchase a 64-bit version of the desktop or laptop you are considering.

To clarify, except in a very small number of cases that I will address, you should be purchasing a 64-bit PC if you are purchasing a new PC.  Yes, Dell and others will continue to carry 32-bit machines for the foreseeable future, but whether you are a generic PC owner, or more importantly a developer it’s time to order a 64-bit machine.  The reality is that as the world continues to move forward the new development money is on 64-bit applications and slowly even devices.  In fact it is the plethora of hand-held devices which will slow the eventual end of 32 bit computing for a little longer but even handhelds will begin that transition at some point in the near future.

Right now pretty much with the exception of the mobile device world, the development world is focused on 64-bit computing (not 100% but increasing every day).  With 64-bits I can have much more than 2 GB of active memory.  Since the maximum value that can be stored in a 32-bit integer is 2GB and since you have to have a number to address each bit in memory this is the cause of the memory limitation. While the operating system can help to fake out this limit  through a few tricks,(for another 1 or 2 GB) the reality is that your application environment has a 2 GB memory cap on a 32-bit OS.  Plus given the power of that 64 bit machine you can run any vital 32-bit applications in a virtual environment and probably still be getting an upgrade in performance.

The question: What are the cases where I shouldn’t purchase a 64-bit machine?  Well if you need and let me stress need as in, must have to do my job, a new laptop and you are working to write software for a 32-bit device (such as a mobile device or the Microsoft Surface) then you can justify getting a new 32-bit machine for that purpose.  Similarly, if you have certain devices like an external scanner or high end printer and their drivers are 32-bit then you’ll probably want to keep a 32-bit machine available to run those devices.  A good overview of the information related to 64-bit limitations is available here: http://windowshelp.microsoft.com/Windows/en-US/Help/41531554-d5ef-4f2c-8fb9-149bdc5c8a701033.mspx#EEAAC

However, in general while this transition will be smoother than the previous 16-bit to 32-bit transition in the long run it will be just as terminal for the 32-bit machines and software.  What timeframe am I talking – well Microsoft is talking about supporting COM based computing past 2020 although I suspect most of that support will be migrated to environments running on a 64-bit machine in a 32-bit virtual environment. I'm not proclaiming the death of 32-bit systems, rather looking at where things are headed in the next couple years.  After all I’m not making a recommendation based on when 32-bit won’t be available or useful, but for what you SHOULD be doing if buying a new system now. 

My core recommendation is to purchase 64-bit on any new PC, I don’t care if it’s for your Mom or a high-end developer / computer gamer – it’s time to order a 64-bit machine.  As for me, well just before Christmas I ordered my in-laws a new PC, like most casual users they have a 5-10 year turn around on a PC and sure enough there in the very reasonable price range for desktops were an array of 64-bit machines and that’s what they got.  So in case you are wondering yes I am following this same suggestion for myself, because in 2-3 years 32 bit PCs will be a thing of the past and people will talk about supporting them for legacy applications that they haven’t yet managed to port to the 64 bit environment.  After all little by little we are even approaching the point where the current internet address system (IP) will transition to a 64-bit version.  You may need to keep the old computer around so you can print if you printer driver isn't supported but don't let a printer drag you into a PC which will be obsolete the day you buy it, you'll replace that at some point to and guess what - all the new ones support... 64-bit drivers.

By the way if you are getting a new PC, definitely get Vista – the XP downgrade is just that but I’ll put my justification for that recommendation in another post.