Pentium 100 Free BSD 2.1.5 kernel gcc 2.7.2.2 -O3 -fomit-frame-pointer options des ecb/s assember 578000.00 133.1% 16 r2 i 434454.80 100.0% 16 r1 i 433621.43 99.8% 16 r2 p 431375.69 99.3% 4 r1 i 423722.30 97.5% 4 r2 i 422399.40 97.2% 16 r1 p 421739.40 97.1% 16 c i 399027.94 91.8% 16 c p 372251.70 85.7% 4 c i 365118.35 84.0% 4 c p 352880.51 81.2% 4 r2 p 255104.90 58.7% 4 r1 p 251289.18 57.8% -DDES_UNROLL -DDES_RISC2