Theoretical speed of 100Mbps cannot be achieved due to some factors from interference, client adapter's specs, encryption/cipher mode, etc and other factors affecting its throughput. Attaining 50% or more speed would OK in my opinion. The cable throughput would depend on both connecting terminals condition because both ends may have firewall or real-time scanner may put some lag in the transmission rate also. If WiFi, DIR-320 we had in our office operates at WiFi b/g only so it can operate only at 54MBbps, max out. Is the model or specs right? Speed is mutually established by 2 terminals connecting. The lower speed specs only would be attained even the rated speed of other end is greater than the other side.