I have a server with a RAID 6 array and 2 clients that I regularly transfer large DV files to and from. The server and both clients have Intel Pro/1000 PT PCIe x1 NIC's. Onboard LAN is disabled in BIOS on all 3 computers. Both clients have identical settings on their NiC cards. Both clients and the server are on the same GbE switch. My question is this - Client "A" can have files pulled from the server side or push them to the server at wire speed - 50-90 MB/s. Client "B" can have files pulled from it on the server side at the same speed, about 50-90 MB/s, but if I try to push a file to the server, either via teracopy or drag-and-drop on a network share, the network utilization goes down to about 1% and the transfer speed is about 2-4MB/s. What could cause this? Both clients have 4GB i-RAM drives on them for testing purposes, and these read 150MB/s according to HD Tune, so I'm confident this is not some obscure setting buried in the "B" client's drive firmware. Also, the clients can move the files quickly between their other internal drives and their i-RAM drives, so I don't think anything is strange there either. I'm wondering if the "B" client has an IRQ issue the other client does not, but I don't know how to track stuff like that down. Any help would be appreciated.