md5 -t native vs VM

[Quartz]

> I have an OSX machine. When I run FreeBSD inside VirtualBox, 'md5 -t' is
> about 5% faster than in the native OSX terminal. Same digest
> (766a2bb5d24bddae466c572bcabca3ee) and everything.
>
> Can anyone explain what's going on?

Also related: 'md5 -t' runs slower (~88%) on a 2.4ghz core2duo than a 
2.5ghz dual core celeron of the same vintage. I'm assuming the extra 
cache and such doesn't matter to md5?