@nula
the pentium4’s rely on intel’s old and dusty netburst architecture with their long execution pipelines. they have a very inefficient instructions-per-clock ratio, especially compared to core2duos.
i switched from a p4 3.0@3.8 to an e6600 @2x 3.5ghz and it’s about three times as fast in renoise now, even though one of the cores is not being used for audio prcessing.
even at stock clocks, any core2duo would outperform your 3.9ghz p4 power plant.
also see this thread for comparison:
http://www.renoise.com/board/index.php?sho…=8184&st=40
there’s one post by me benching my old p4 and another one with the c2d.