While I don’t find this kind of benchmark too exciting I will add that the difference is greater on OS X; well over a hundred times faster for 5. It’s easy, for me anyway, to forget how well tuned 5 is…
# This is perl 5, version 18, subversion 2 (v5.18.2) built for darwin-
+2level
moo@cow[22]~>time perl -E 'my $s; for ( 1..1_000_000 ) { $s+=1/$_**2 }
+; say $s'
1.64493306684877
0.111u 0.000s 0:00.11 100.0% 0+0k 0+2io 0pf+0w
# Both the last two Rakudo builds of 6.c produced same results
moo@cow[30]~>time perl6 -e 'my $s; for ( 1..1_000_000 ) { $s+=1/$_**2
+}; say $s'
1.64493306684877
16.198u 0.300s 0:16.55 99.6% 0+0k 0+0io 0pf+0w