OpenVPN Server - CPU is pegged out

I am configuring OpenVPN to act as a SSL tunnel for a remote location. I have OpenVPN1 at our current location acting as a server then OpenVPN2 at the other location that is acting as a client but is also acting as a DHCP server to machines behind it so they are basically connected to the local LAN. Everything is set up fine and I can talk from location A to location B with no problems like everyone is local. I am however having some performance issues. OpenVPN1 CPU is pegged to 100% the entire time I am copying or doing any type of activity through the tunnel. I expect some CPU usage going up but nothing like this. It's really killing my performance. OpenVPN1 is running in ESX right now with 2 gig RAM and 4 procs with unlimited bursting capacity. I am using AES-192 encryption with a 1024 key. Any idea how I can get my CPU down on OpenVPN1 and my download/upload speeds higher between the tunnel? Thanks.

edit: Turning down the logging helped boost the throughput a little bit, but I am still fairly shy of where I believe I should be. Also I am still maxed out on the CPU. Does anyone have any ideas? I am really stuck on this.

Solution 1:

what's the speed of internet connection between both ends? openvpn on modern hardware can easily handle 100Mbit/s or more of traffic.

do you run tun or tap mode? tap tun/routed should give you better performance.