which RouterBOARD can support 100pc/user at the same time?
Mikrotik RB450G can support 100pc/user at the same time?

any routerboard product can do that. yes, RB450G is an excellent choice

any routerboard product can do that. yes, RB450G is an excellent choice

the routerboard can afford it?
will it overload if 100user / device use the internet thru this router at the same time?

It will not overload. it is very powerful.

It will not overload. it is very powerful.

what is the maximum device support for this router?
400 pc/ user?

what are these users doing, and what configuration will you put on the router? if you will have no speed limits and firewall, you can have thousand users.

what are these users doing, and what configuration will you put on the router? if you will have no speed limits and firewall, you can have thousand users.

i will use this router as a hotspot, and it will be 70-100 user use it at the same time..
and all this user just use it to online, suffer internet...and i will do some QOS on it to limit each user bandwidth, so that it will not affect others user internet speed...
will this overload if 100 active user/device use it at the same time?

what are these users doing, and what configuration will you put on the router? if you will have no speed limits and firewall, you can have thousand users.

i will use this router as a hotspot, and it will be 70-100 user use it at the same time..
and all this user just use it to online, suffer internet...and i will do some QOS on it to limit each user bandwidth, so that it will not affect others user internet speed...
will this overload if 100 active user/device use it at the same time?

100 users is not much for this router if they are just general internet users. but so many things can effect The router performance. You mention Hotspot network. How are you planning to implement the Hotspot? are you going to use a radius server for authenticating clients? simple queues or pcq's, What firewall are you planning? How much bandwidth will passing through the router etc etc

100 users is not much for this router if they are just general internet users. but so many things can effect The router performance. You mention Hotspot network. How are you planning to implement the Hotspot? are you going to use a radius server for authenticating clients? simple queues or pcq's, What firewall are you planning? How much bandwidth will passing through the router etc etc

the hotspot, im going to set username and password to 100user, and set the duration for the user for 4 months for each user.
and i think there is no firewall set..
i just need to do some QoS...
i want the speed 30% for suffering web, 40% for p2p, torrent, and 30% for gamming...

and the internet speed provide by ISP is 20Mbps...

100 users is not much for this router if they are just general internet users. but so many things can effect The router performance. You mention Hotspot network. How are you planning to implement the Hotspot? are you going to use a radius server for authenticating clients? simple queues or pcq's, What firewall are you planning? How much bandwidth will passing through the router etc etc

and i think im not going to use radius server..