we have about 6 servers in our environment all with gigabit Ethernet cards connected to a cisco 3650 which has the ports set to 1000 full. On the servers the only option for 1000 full is auto neg. 3 servers are running server 2008 r2. 1 functions as our primary dc, and antivirus server, one as our backup dc and as our netvault backup server, and the 3rd is our sql 2012 server.
When we try to do file transfers from one server to the others we see a speed of around 10-15MB/Sec. I can start up 7 or 8 file transfers from the same point to another point and see the same speed on each one. of around 10-15MB/Sec.
we initially reached out to cisco thinking the slow speeds were due to the switch since it was affecting multiple devices, however they found that the tcp window the server is showing to the switch is low and that the transfer speeds at the switch were as fast as it should be for gig full. We at this point updated the bios, network card firmware and drivers to the latest release and saw little to no improvement in transfer speeds.
Can someone please give me some advice. We are almost to the point of contacting the pay per case support at Microsoft.