I've often been asked this by customers and I've come to the conclusion that it's very difficult keep your hardware current by doing incremental upgrades.
We have a tendency to stick with what works -- if it ain't broke, don't fix it. So, when it comes time to replace that Celeron 333 in an LX board that is serving you so well, you find that you will have to change your motherboard as well. And since you'll be getting a newer PC133 motherboard, well, you might as well get PC133 memory and a nice AGP card that will now have enough power behind it. Maybe a new hard drive would be nice to hold all those games you'll be playing with the new machine. . .
See where I'm going? If you're going to be upgrader, you really have to stay on top of it. That means upgrading when you don't really need to -- when your system is already doing everything you want it to. Keeping your hardware current will often involve a small CPU upgrade, say, A/550 to A/700, or a quick video swap, say, TNT2 to GF256 SDR. It's pretty silly, when you think about it.
I'd say a better approach would be to build/buy a new computer every once in a while and get rid of the old one. The main advantage of this strategy is that it doesn't dismantle a completely good system leaving you with a handful of old parts. Your old system still retains its value and can be sold off or handed down to a friend or relative. And it's nice always having a new mouse or keyboard or monitor.
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