I recently upgraded from an athlon 500 to a t-bird 800, both with 128mb ram and same hard drive. went from pc100 to 133 also. Not much difference on windows apps. i am sure gamers notice the difference, but i was kind of disappointed. i usually recommend to customers that it becomes worth it to upgrade if you double the processor speed, but i am beginning to wonder if the processors now are so fast that the major factor in speed is hard drives?