Can somebody explain the basic differences between processors such as AMD and celeron etc. For instance an AMD xp2800, does it run as fast as a celeron 2800 or a P4 2800?
They are made by different companies and use different technologies to ramp the processor speed up (Hyper Threading being one of them). At the end of the day, you get what you pay for though AMD processors are still very good if you're looking to save a bit of cash.