It is important to note that the Maximum Data Transmission Rate is not the same thing as Process Data Throughput. Max Data Rate represents the nominal theoretical maximum amout of data that could be transmitted on the wireless link. This will include ALL data, such as TCP/IP overhead messages, network 'housekeeping' traffic, etc., as well as user process data. Process Data Throughput is the actual volume of user process data transmitted over the wireless link, excluding all the overhead. For this and other reasons, the actual Process Data Throughput will always be less than the theoretical Max Data Rate.
Some other factors that lower Process Data Throughput below the Max Data Rate are: pecularities in specific wireless and wired network environments, in-band RF interference, total number of radios in the network, number of repeaters in the network, and most importantly, Ethernet packet size (the smaller the packet size, the higher the ratio of message overhead to useful process data.)
Therefore, you should always expect your real-world Process Data Throughput to be less than the Max Data Rate set for the radio system.