Re: copying a 12GB file
FTP would probably be the fastest, but scp (file transfer over SSH) is
probably already on both machines if they're both Linux. PuTTY is an
excellent SSH/SCP client for Windows (and Unix) if you need cross
additional comment - iirc, it's possible to choose weak encryption for
ssh that might actually speed it up a bit.
You probably don't want to use SSH Compression as I've seen it actually
slow down file transfers over fast LAN links. The SSH encryption might
slow down the transfer as well, so the transfer speed might depend on
the speed of your CPUs.