The general wisdom says that yes, method calls are slower than function calls. (In some cases DRAMATICALLY slower.) For a simple case though, lets find out:

use Benchmark;

package Foo;
sub bar {
        1;
}

package main;
timethese(1000000,
        {
                method => sub { Foo->bar(); },
                func   => sub { Foo::bar(); },
        }
);
[download]

Drumroll....

Benchmark: timing 1000000 iterations of func, method...
func: 1 wallclock secs ( 1.93 usr + 0.00 sys = 1.93 CPU) @ 518134.72/s (n=1000000)
method: 6 wallclock secs ( 4.95 usr + 0.00 sys = 4.95 CPU) @ 202020.20/s (n=1000000)

Yup! When in doubt, Benchmark.