Shoutbox

The Core 2 processors are a lot faster than a 3GHz Northwood, but it's quite possible that your current system is fast enough.  Does anything you do take too long or any games you want to play don't play smoothly (or at all)?

My desktop machine is similar (3GHz Northwood) and I can tell my Core 2 Duo Macbook is a lot faster, even being a laptop.  The desktop is still better for games, because it has a halfway decent graphics card.  It is fine for everything I do with it now.  When that changes, I will replace the whole machine.

That gets us to the next issue: upgrading a computer that old is pointless.  You can't just buy a CPU and motherboard -- you will also need new RAM, new graphics card, and new power supply.  That's 85% of the cost of a computer, so just buy/build a new one.  You could reuse your old drives and perhaps the old case, but it would save you very little and leave a heap of worthless old parts.  The old computer in one piece has more value.

Before the 3GHz computer, I had a nice (for the times) P4 1.8GHz, which was only 1.5 years old.  I replaced it for a reason (a specific game I was into then didn't play as well as I wanted) and gave the 1.8GHz to my mother, who was previously using some piece of trash.  She only uses the computer for web, email and digital picture collection, so the 1.8GHz should keep her happy until it fails beyond repair.