shouldn't the pre-compiled regex run faster because of pre-compilation
Both your regexp and your program are fairly trivial. Even if there wasn't any caching involved for non-precompiled regexes, I doubt you'd notice the difference. Whether that's the case for your real $text, I do not know.
Perl has been caching compiled patterns since the 20th century. (5.004 or 5.005, IIRC). This is why /o is usually pointless (if not broken).
Often, the compilation time is dwarved by the runtime anyway.
You'd have to be careful -- if you interpolate your compiled pattern into a larger one, you're paying the price of compilation twice.