I've never done tests myself, but here's what the Camel has to say:

The logic of abstraction comes at a price. Because of the late resolution of methods, an object-oriented solution in Perl is likely to run slower than the corresponding non-OO solution. For some of the fancier techniques described later, it could be a lot slower. However, many common problems are solved not by working faster, but by working smarter. That's where OO shines.

Camel 3rd edition, section 12.3

I could swear I've seen "20% slower" in an earlier version of the Camel, but I can't find it now. Obviously, depending on the code/hardware, YMMV.