Copying from 1 Linkstation to Another

[johnsonjam]

So I have a LS210D in one of my stores.  I then have a LS420D in my primary office.  I am using the LS420D to put my file backups on but would like to copy them down to my LS210D.  The problem I am having is if I try to just use the copy feature via windows I am only writing at speeds of 900Kbps.  If I use Terracopy or similar software I get the same speeds.  If I use software called "LanSpeedTest" I get around 8MBps.  All the software does is write a file to the drive and then read the file.  So I know there isn't an issue with my network.  I am looking to send about 150GB of data down.  Is there another feature that I am not using on these NAS devices that could just copy directly from one to another, is there a different model that could do these features?

Thanks in advanced.