How Often Should Computers be Upgraded?

When I was a kid, I figured that everyone ought to upgrade their computer at least every year or two. I continued to think that until recently, when I was shopping around for a new computer for our home. I realized that I wouldn't actually get that much of a noticeable increase in capability by buying a new machine. I'd get a number of "nice" things, but nothing that was really necessary. So, instead of buying a new computer, I decided to address the specific issues that I had:

1. I had difficulty running some heavy duty mathematical software, so I doubled the RAM in the computer from 1 GB to 2 GB. This cost $30. It works fine now.
2. Netflix streamed videos were a bit choppy (because of the new SilverLight player). I discovered that Boxee can play Netflix videos better than a web browser, and the choppiness problems went away.
3. We were a little bit low on hard drive space. I moved most of our media files to an external drive.

Now the three-year-old laptop does everything I need it to do, and it only cost me $30 plus a little bit of work. Now I can wait another year or so before buying a new computer!

If you're deciding whether to buy a new computer or upgrade your current one, here are my recommendations:

1. If you can upgrade your RAM to at least 1 GB, do that. If you've been running Windows XP or Mac OS X with only 512 MB, you'll be surprised at how much better it works (if you're running Linux, you don't need this very basic post about computers). Make sure to add the correct RAM for your computer (check out NewEgg).
2. If your hard drive is more than 70% full, buy a larger one (perhaps external).
3. If your computer can't be upgraded to 1 GB RAM, and you want to use it for modern software and web applications, you're probably best off replacing it soon.

As a last note, from a productivity standpoint, it can be beneficial to spend almost as much on the monitor as on the computer itself. Studies, such as this one from the University of Utah, seem to show that larger monitors result in better productivity. Currently, a 24-inch monitor seems to be the offer the best balance between affordability and size - or, you could always hook up multiple monitors...