What is an acceptable transfer rate?

I am new and have lots of questions, sorry for multiple posts.

I have a 1 gig network and I am using a 6T Duo in a Raid1 config. I am also uisng Win8 64bit, 8 G ram on a wired network.

I just moved 8G+ files to the Duo and the best transfer rate was 25 MB/s and slowest at 3MB/s. I am trying to understand expectations. Is this the norm?

I used the Win8 graphic to monitor the transfer.

Hi, some users are able to get between 50/60 megabytes per second. Check the link below for some suggestions you can try to improve the transfer rate. 

http://community.wdc.com/t5/My-Book-Live-Duo/Stupidly-slow-My-Book-Live-Duo-2TB/m-p/566764#M4420

When transferring large files to or from the My Book Live performance may be slower than expected