Is maximum throughput of a station based on the radio or an individual SSID?

Also does having two SSIDs make an AP more efficient handling client data i.e. faster?

cheers, dom

All devices connected to the same Radio, and on the same channel in the receiving area share the available bandwidth of that RF channel. Consider the radio channel as layer 1 which is shared. WLAN/SSID are layer 2 separations and are used to provide different services (encryption, authentication) for different types of devices or user communities. Since each WLAN/SSID must transmit a beacon to announce its existence, so that multiple SSID’s are slightly less efficient due to this small overhead. Additional WLAN/SSID’s are recommended only to provide different services or to segment traffic into different VLAN’s. The later can be accomplished with a single SSID with Dynamic VLAN feature of 8.2 if you are using 802.1x authentication.