On my machine (an Athlon64 with amd64-freebsd) grep is always faster than perl. Using an 8MB test file:

$ time perl5.10.0 -ne '/./ and print' /boot/kernel/kernel > /dev/null
0.070u 0.015s 0:00.09 88.8%     1490+1246k 0+0io 0pf+0w
$ time grep -a '.' /boot/kernel/kernel > /dev/null
0.026u 0.000s 0:00.03 66.6%     114+1056k 0+0io 0pf+0w
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