athlon1000, 256kB
pentiumII 266, 512kB, 2.4.31 SMP
pentiumII 266, 512kB, 2.6.12.1 SMP
(note that the first P2 run only confirms that the linux 2.4.x SMP scheduler sucks frozen goats through nanotubes, with 2.6.x its right back in the pattern seen on the other hosts)
so, it does not seem to be just the size of the cpu cache.
makes me more interested in seeing the code used in >>169 ...