Comparing the performance of the 1.3/1.33 Ghz Athlon to that of the Pentium 4 is not straightforward. In the current computing environment, the Athlon is the clear winner with its fast integer processing and FPU, but looking forward things get somewhat more difficult. The Pentium 4 has abandoned much of its x87 FPU power in favour of Intel’s newer SSE-2 instructions, and where these are used (currently only SSE-1, but it is compatible) the Pentium 4 shows performance advantages. As the Athlon lacks SSE-2 (and the original SSE-1) in favour of AMD’s own 3dNow! instruction set, future applications may (please note that the emphasis is on the word may) not run as well on the Athlon. This though is by no means certain and the power of the Athlon’s x87 FPU may well be sufficient for some time.
hope his helps
again the chips have a run life as to when they will be discontinued so date of manf may be later as stock is cleared