AMD 2600+ ~$250 (not yet available)
P4 2.53 $243 (newegg.com)
Overall, neither signifacantly outperforms the other and they're about the same price. However, the P4 has SSE2 (Streaming SIMD Extensions 2) support while the 2600+ does not. In these applications (usually multimedia software, for example ULead's VideoStudio 4) that are SSE2 optimized, the P4 signifacantly outperforms the 2600+, so in that case I choose the P4.
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