Question Slow speeds on a VPN router(Asus RT-AC56U) using ExpressVPN


Sep 6, 2018
Like the title says, I'm experiencing very slow speeds when using my VPN router with ExpressVPN's own firmware even when using an ethernet cable, the speed I get when I connect to the secondary router and disable the VPN is around 250Mbps but as soon as I enable the VPN that drops to around 25-30Mbps, I have tried all the different protocols and I've talked with their support for hours and nothing helps. The router I'm using is the Asus RT-AC56U. Any help is greatly appreciated. Thank you.
VPN and even more so for openvpn, is cpu intensive. Many routers have less cpu power than some cell phones. Still even the very fastest routers only get 30mbps partially because encryption is single thread so multiple processors does not scale it.

The only true solution is to use a actual processor rather than the toys in routers. Now you can get close to 200mbps with a very tiny number of consumer routers. The cheapest one is asus ac86u. It has a very high clock speed but the key reason is it has special encryption acceleration instructions. These instructions are also why PC cpu can get such high rates.

There support guys are idiots if they do not know this limitation. Now they may be comparing it to the software clients you run on the pc rather than the router.

You have few options. You buy a router with a CPU that has the instructions and be happy with about 200mbps or you use a dual nic pc an load a linux firewall with vpn on it. Even with a pc you need to use fairly modern equipment if you want to get say 1gbit of vpn throughput.