I recently acquired a HP ProLiant DL-380 G3 server and moved my Windows SBS 2003 server into this hardware. Today, while copying large files from the server to the workstation, I'm seeing that something is limiting or throttling the amount of bandwidth between the server and the workstations. I can copy a 400,000 mb file from my laptop to my desktop workstation through the same switch, same subnet, same everything, in about 45 seconds. It took about 12 minutes copying the same file from the server to either the desktop or the laptop. When I look at the network traffic with a sniffer-type application (Network Instruments Observer) I see a definite limiting as the traffic curve looks very much like a table-top at the 1k/s value.
Since the network is capable of transferring the files far faster, and the PCs can transfer files between themselves, I'm left thinking the server is the source of the throttling. There must be something on the HP ProLiant DL380 G3 server, it's installed drivers, management software, or other HP server management that is limiting the transfer rate.
I have checked - QoS is not installed in the network properties. I have looked through the network connection properties and found nothing that would seem to be about limiting bandwidth or throttling a connection.
It is limited in both directions. When I started another copy from the server, the amount of traffic traveling over the network increases, so there is capacity. But the speed of sending the data is still pretty slow. I'm using the 1gb LAN connection on the DL380 server and it says its connected at 100. I'm using an old 3COM 10/100 hub/switch that lets me sniff the network.