Is it 11Mb or 11MB, here's a good explanation from another site
A 10/100 card running at 100mbps would be capable of 100 million bits per second. A byte is 8 bits, so devide that by 8 to get 12.5 megabytes per second.
Now, this does not take into account the overhead for TCP/IP packets. You'll see a little less actual data throuput because of the extra information required by TCP/IP to send that data (information about what IP is sending it, what IP and port it is destined for, etc...).
Now, this also is assuming an ideal transmission path. Your cabling might make some difference. For instance, you might see signal loss and packet loss over long distances or due to external interference. Also, kinks or tight bends in ethernet cable can cause packet loss and lower throughput as well due to resending packets. Poorly made cables with bad or loose connections can also severely hinder network performance.
If you use a hub instead of a switch, you will also not see your 100mbit totally realized due to all of the machines on your network sharing the 100mbit through that hub. Switches help to get rid of that bottleneck and get rid of collisions (two machines talking at once).