Gigabit networks with low quality cables
I have 2 computers attached to a Gigabit switch and both these computers have NICs that support 1 GBPS speed. However, I noticed that transferring files between them was slow so when I inspected the speeds I saw that one of them was operating at 100MBPS and the other at 1GBPS.
At first I went into the driver config setup and fiddled around with half and full duplex to see if that would make a difference. After a bit more research I found a comment that a network cable might be the culprit and that some network cables (e.g. Cat 5) do not support speeds over 100MBPS. I didn't believe that could possibly be the problem but it was easy to test so I switch the cables and the slow speed moved with the cable. So replacing the cable did the trick. Apparently Cat 5e and Cat 6 are what you need to get the higher speeds.
I'm now transferring data at 10 times the original speed.