This is perl, v5.10.1 (perl-5.10.1*) built for MSWin32-x86-multi-thread
##</code><code>##

$ perl -MBenchmark -lwe "my$x=q//; print timestr(timeit(eval($ARGV[0]),sub{$x .= (q/x/ x 1000);}));" 10_000
32 wallclock secs (20.41 usr +  9.34 sys = 29.75 CPU) @ 336.13/s (n=10000)

##</code><code>##

>perl -v

This is perl, v5.8.9 built for MSWin32-x86-multi-thread (with 9 registered patches, see perl -V for more detail)


>perl -MBenchmark -lwe "my$x=q//; print timestr(timeit(eval($ARGV[0]),sub{$x .= (q/x/ x 100);}));" 10_000
33 wallclock secs (20.53 usr +  9.47 sys = 30.00 CPU) @ 333.32/s (n=10000)