On my Athlon (64bit, Linux, Chicken 4.4.4). The +max+
parameter in the benchmarks was 10000000.

YMMV!


                scheme    specialized-io   speedup
-------------------------------------------------
write fixnum    14.602      5.303          2.7535
read  fixnum    58.208     11.706          4.9725

write flonum    37.003     21.647          1.7094
read  flonum   100.367     15.626          6.4231

write complex   89.361     56.020          1.5952
read  complex 3076.952     59.476          51.734
-------------------------------------------------