How to maximize file transfer speeds? We're trying to transfer large files from NY to LA, from one Mac to another.

Both sites have 100/100 mbps internet. Both report full speed at www.speedtest.net.

But we've tried AFP, SMB and SFTP, and can't get it to go any faster than 20mbps.

Tested with iperf -- with parallel connections got up to 16-20 mbps.

However, we are doing this over a LogMeIn Hamachi VPN. Does that throttle/limit the speed?
Using lftp with sftp and pget -cn10 I was able to get the transfer up to 99 mbps!