If you are copying files with Windows Explorer to/from some other PC or NAS, such speeds you noted are normal even with a gigabit network. Why is well discussed so I'll suggest you try other speed tests.
A common gaffe is home made cables. Folk always get the pairs wrong and some are so upset about that that they'll stamp their feet and insist the pairs are 1-2, 2-3, 3-4, 5-6 and 7-8.
After upgrading my home network I've been struggling to make sure all wired devices actually take advantage of gigabit connection. Any advice will be much appreciated.
So first off, my setup:
cable MODEM (22 mbit/s) - linksys EA3500 wi-fi gigabit ROUTER - in-wall cables - linksys SE2500 gigabit SWITCH
Pc with gigabit ethernet is connected to ROUTER, while in another room I have ps3 and xbox hooked up to the SWITCH.
I checked that PC and PS3 use gigabit, however simple data transer over the network yields 7,5 MB/s, which is somewhat below fast ethernet standard and nowhere near gigabit transfer speeds. Now I know that theoretical speeds are just a specification, but I had hoped I would get faster that the slower standard I had been on before. And at this speed I know it's not the hdd that is slowning things down as it would be at least 50-150 MB/s for sata drive.
I am somehow not convinced that there isn't a bootleneck somewhere, but I can't pinpoint it. I did check all the status lights on switch and made sure the settings are right on any device that is configurable, I am unable however to check if router sends out gigabit signal.