The personal computer has been around for a long time now and is the key tool for most knowledge workers – a major driver of their performance.  Despite this it never ceases to amaze me that most people struggle to know what sort of computer to buy.  This doesn’t just apply to ‘normal’ people, but techies too.  Most people cannot understand the technospeak of the IT industry which seems designed to confuse buyers.  However they do usually understand their needs.  IT staff in comparison understand the technospeak, but often do not know how their end users will use the machine.  This was brought home to me recently when a techie decided the best machine for an incoming CEO would be a high-spec 17 inch laptop, just as he would desire.  The CEO had different ideas and a tiny little 12 inch machine was quickly procured.  So, what should we be looking for when buying a machine?

Performance

Any modern PC will now do the basic tasks of email, web browsing and writing Word, Powerpoint and simple Excel documents.  Even lightweight netbooks can do this.  For these tasks the size of the processor and memory is going to be enough.  Spending more money on performance brings only the benefit of faster switching time when running multiple applications at the same time.  Historically applications (particularly Microsoft ones) suffered from becoming larger over time as features and bug fix packages were added.  This is one of the reasons why machines seem to get slower over time.   With Windows 7, Microsoft have for the first time made a smaller Operating System than its predecessor so that it will function on Netbooks.  Hopefully it will stay small.  Thus the actual size of processor and size of memory you need to run these applications will steadily change over time.

If you are interested in software development or developing sophisticated Excel sheets, you will need more power than for these basic tasks.  If you are into gaming, video or picture manipulation, music creation or Computer Aided Design, you need a serious amount of horsepower. 

The relative importance of processor size and memory depends on what you are doing.  In my experience memory is a better investment than processors, however it is always worthwhile Googling the best configuration for your particular application needs before parting with hard earned cash.  For example, it is not a well known fact that software development applications (e.g Visual Studio) actually perform much better if you buy a faster hard disk – they spend a lot of time writing small files to the file system, so the disk becomes the bottleneck.  Buying a powerful laptop with a slow disk  (typically 5400rpm rather than 7200rpm or even 10000rpm that you can buy as options) is not the best return on investment.

Finally, desktops offer considerably more performance for a given investment than a laptop.

Form factor

From a performance point of view, the most important thing in my opinion is screen size (and number of screens).  The bigger the screen area, the easier it is to work with multiple applications simultaneously.  Screen area needs to be considered in terms of both size and number of pixels (Note that not all computers can handle every screen resolution – always check if you are buying a new monitor for an existing PC).   If you work with graphics, the colour accuracy of a screen is also important.   Larger screen areas allow, for example, easy copying and pasting between two documents, or opening the help screen alongside an application without compromising its use. If using Excel or a CAD tool, the amount of information visible at one time can be vastly increased. I would estimate an increase in performance of around 50% on many computer based tasks.  This article  covers research on the impact of screen size on productivity showing a 100% increase when moving from a 17" to a 30" display for common tasks.   The only time I compromise on screen size is with a laptop.  If I’m using a laptop, it is because I’m travelling, and I like to keep my laptops small and lightweight as I have to carry them on and off trains and aeroplanes.  I’d be less concerned if I travelled everywhere by car.  When I’m buying a laptop, size and weight are my primary concern, as long as the laptop is useable.  For me, a 12 or 13 inch screen is optimal.  My second concern with a laptop is reliability.  Some brands (In my opinion Toshiba, Lenovo and some HP machines) are much more solidly built than others with features like drop-protected hard-drives and spill-proof keyboards (and you pay for it).  Business oriented machines tend to be better built than consumer oriented machines.  If your travel arrangements are less arduous than the typical consultant, then cheaper machines will probably suffice.  I would also seriously consider buying an extended warranty as repairs are expensive.  Finally I consider battery life.  Here there is usually a compromise with performance.

When buying any computer, I also am careful to hear it first (or find a review that mentions sound).  I once bought a server that had amazing performance.  Unfortunately it sounded like an aircraft once running (all those cooling fans) and I couldn’t bear the sound for more than an hour, which rather hampered my use of it.

Lastly, look at how much space the computer (especially desktops) takes up.  Some machines are huge, and if space is a premium, then a smaller model can be a good choice.  The disadvantage of this is that you lose some expansion capability, so if making this choice make sure the base PC has ports for the equipment you need to plug into it like Firewire for video cameras.  For the more aesthetically inclined, some machines are also much prettier than others, but you pay a premium for this.

Software

The most crucial bit of software is anti-virus.  Beware, they are not all alike.  Some of the most popular ones really slow down your PC as they run all sorts of stuff in the background.  Google which is the fastest anti-virus for your Operating System and buy it – do not just use the one installed by the computer supplier on a free trial!  If you are a home user, there are some good free versions available.

For working with documents, you can use OpenOffice or Google Apps which are free.  I’ve tried this, and being a relatively sophisticated user who exchanges documents with people in numerous organisations have always ended up back with Microsoft Office.  The main issues are exact format compatibility and the faff of having to remember to save documents in Word format (which can also compromise version control – same document, different file formats).  I think these free versions are perfect for home use, and can be used if most of your business communications are simple or you can all use the same application internally within your company.  However if you are exchanging documents with people in numerous organisations it is hard to avoid Office (despite the cost).

Apple vs Mac

I run both of these at the moment.  Now Windows 7 has been launched, I think the Operating Systems are a good match for each other, and I think preferences are a matter of taste.

The Mac has a few quirks I still haven’t got used to after over a year of use.  There is a much greater emphasis on keystrokes to use the OS quickly compared to Windows.  My Mac is I think an overall better experience as the hardware and software are tightly integrated.  The Mac tends to prefer a single large screen (as the menu is at the top of the main screen).  Windows is more intuitive on multiple screens.  My big bugbear with the Mac is that I still have to run a Windows machine.  Word, Powerpoint and Excel work well on the Mac (unless doing Excel sheets of epic complexity) and putting the Mac on corporate networks is now quite simple.  However the moment someone sends me Visio or Project files, I have to boot up a Windows Virtual Machine which is less than ideal and means I might as well be running Windows in the first place.

And of course the Mac is much prettier.  In a consulting environment where you work with lots of Windows based colleagues, I’d probably run Windows.  For other purposes the Mac is better.  That said Windows runs like lightening on Mac hardware as a dual-boot machine, so you CAN have it all.