Performance of system("rm x.*") vs unlink()?

I'm maintaining a Linux legacy system which maintains millions of small files in a large storage array. (yes, filesystem nightmare)

In the C++ code I found files being deleted like system("rm -f /dir/dir/file.*")

I suspect using unlink() is going to be a lot faster, but how much faster? (I can't really test it in production)

Anybody have some comparative data on this?

The old code is already fragile and replacing the handy system() calls with unlink() and getting the globbing to work, etc, is a good chunk of work...