we have some "old" supermicro server X5DPR-8G2+ and X6DHR-8G2 with both 82546GB NIC.
What happens is that while transferring a huge file (let's say a DVD ISO) the file transfer starts with high speed and after some while the speed slows down to some MBytes.. This is a problem because we would mainly use the servers for rsync's backup
This happens using scp, smb, http and with debian, centos, suse, windows 2003. With Linux I tried installing the "original" supported versions but also the newst with up-2-date drviers from Intel.
The hard disk is SATA I, the connection was done throgh a switch and directly to the server, same results.