How many open VPN clients can be connected to server?

[Larry-hsm]

We have a project, and we want to use open vpn for our project, but there is an issue that we don’t know how many clients can connect to an open vpn server.
I know it may be related to hardware configuration of server PC. If that, could you please tell me how many clients can connect to open vpn server that have a standard hardware configuration.
I think it is better to take a instance for us, like 200 clients can connect to server, the server’s hardware configuration is:

CPU: Intel(R) Core(TM) i3 CPU 540 @ 3.07GHz (4 cores)
2GB RAM
Linux 2.6 (Debian 6)
……

If we add the RAM to 4G, how many clients can be connected to server? and if we change a better CPU? Could you please explain it to us in details?

PS: we don’t use this hardware configuration, I just take it for example.

[Larry-hsm]

is any one know about it?

[maikcat]

i have a working installation with 80 clients running on a
hp ml 110 G5 with no problems...

this issue was discussed in the past but i dont think there was
a clear answer...

i believe with 200 clients there is no problem with a core duo class cpu..

Michael.

[VPNTutorials]

CPU is normally the bottleneck. Just monitor your server and check your CPU usage when the number of connected users is high.

I have a Atom server and it can handle at least 150 users although not all users are using too much bandwidth.

[TavisCoelho]

150 users for one IP?

[VPNTutorials]

150 users for one IP?

Is this question for me? No the server has a /24.

[janjust]

what he meant is that 150 users route traffic via a single (server) IP and the answer would be yes.

The current builds of openvpn are still monolithic and benefit greatly from clockspeed, not from multicores. So if you want a fast openvpn server then get a CPU with the highest GHz count, not the number of cores. And yes, if the clients do not consume too much bandwidth then an Atom CPU can easily handle 150 clients.