I wouldnt really compare the sempron to the celeron....the celeron is usually 1 step back from the P4 as now the P4s are 800bus and the celerons are 533bus and they also lack the cache...Semprons just lack the cache and thats all thats stopping them from becoming A64's plus the cache isnt a huge deal as it already has the memory controller and the latency is so low anyway..