The cache is generally the most decisive factor in the tradeoff equation between the price and performance. Considering the L2 cache on some of the chips, you can easily understand that Athlon, P4 and PIII, having 256K or more L2 cache are the once with higher performance, in other words power chips.

Looking at the budget chips, you immediately notice that Celeron has 128K and the Duron only has 64K. Celeron is actually almost like a PIII with half the cache disabled. These numbers shows that the main budget issue for CPU manufacturers is to put enough cash on the chip.

You should consider the difference between the bus speeds: in the case of Athlon and P4, the bus speed between the Cache and the CPU can be 200 or 400 MHz respectively. This can give your system a major boost when you are using cache intensive utilities. The new CPUs are coming out with quad speed pushes and base 200MHz which results with 800MHz FSB like the new P4.

The numbers you would see under the name “Micron” in a CPU comparison table is basically the size of the transistors. As the number get smaller, the manufacturers can put more and more on the CPU die. The smaller transistors you have on your CPU, the smaller the CPU die becomes. The smaller the CPU die, less power is required and less heat is produced.

The CPU instruction set is the total code which tells your CPU how to process its data. The more sets you have on your CPU, the more efficient it is most likely to be. However, on this point Intel (Pentium) and AMD does not follow the same path. Intel made the first attempt to improve the basic instruction set by adding the MMX support for multimedia.

The difference's between the CPU's are getting smaller as each company sees the advantages of their rivals technology and tries to either use or emulate it. It is really hard to choose which one is better. So a good advice would be let your wallet decide which CPU your system will use.