As the title sais, I don't really know how to compare processors to each other. I'm going to buy a cheap laptop and was wondering which one is the best: Intel Mobile Celeron 900 - AW80585NG0491MA AMD Mobile Sempron SI-42 - SMSI42SAM12GG AMD Athlon 64 TF-20 - AMGTF20HAX4DN Also, the athlon comes with 3 GB RAM instead of 2 but the celeron comes with a 250 hardrive instead of 160, but you don't have to consider this. All I want to know is which one will give me the best performance. Maybe the difference is not so big?