I have got an RB800 with 3 sectors, and have about 75 clients connected, totalbandwithis about 12Mbps. My routerboard only uses max 10%cpu
How many client can I connect on that 1 board?
Depends on your signal quality and type of traffic. One person running bittorrent can fry a network.
Three radios? 802.11n? What is your lowest connection speed in your wireless registration table?
In best case (good CCQ, clean frecuencys, etc), you could install about 100 clients on each radio (using nv2 and 40mhz channels)
Regards
Our APs (4xxAH) can handle around 100 CPEs per sector (althougt we usually try to have the number significantly lower) in 802.11a (RTS/CTS) mode. The problem is not the amount of clients but the total bandwidth used/required.
An I would never put 3 cards in one box. We strictly use only one card (from the same band - i.e. we allow mixing 2.4Ghz with 5Ghz) in a single box. There is so significant interference between the cards so you have to use very distant channels. From my point of view the RB800 is too big (= too expensive) hammer for the usual AP.