Network Speed Issues with NAS, SMB vs FTP

I have a NAS server on my network (Thecus N4100 Pro) it runs both an FTP server and a SMB server. I'm trying to backup some of the more important contents (about 1TB) to some unused hard disks prior to performing a firmware update (just incase) the issue is I connect to it thru SMB and I'm getting over 600 Gbps of file transfer, when I connect to it with FTP I only get about 25 Gbps. Now I'm having an issue where the SMB connections randomly dies (why I'm updating the firmware) and that makes me suspicious of the FTP also but I'm wondering if somebody has any ideas because FTP will take days and SMB has to be watched like a hawk because when it dies the file it was working on doesn't get deleted from the destination and is the correct file size but just ends with a blank file. (Also if the SMB is a move the file also gets deleted from the source, I lost a few files this way before I realized the issue and now I only copy to and from and delete once I confirm it's there.)

Tried with following
FIleZilla 3.6.0.2 (only FTP client I've found that will work)
I've replaced the cable from the NAS to the switch
I've replaced the Switch (2 gigabit switches and a 100base t switch)
I've tried 3 different computers (Windows 7 Pro 64, Windows 7 Home 64, Windows XP Pro 32)
Jumbo frames are turned off
NAS has a static IP configured in the NAS outside the DHCP's assignment range

Thanks in advance for any ideas you have.