openvpn and system overhead

[Eugene Grosbein]

On 19.04.2019 23:42, Wojciech Puchar wrote:
>> because of unavoidable and big overhead due to constant context switching
>> from user land to kernel land and back. Be it openvpn or another userland daemon.
>>
>> You need either some netmap-based solution or kernel-side vpn like IPsec (maybe with l2tp).
> 
> well it has to cooperate with multitude of clients like windoze, 
> point&click routers etc. that's why openvpn.

Windows has stock support for IPSec with and without L2TP and has no stock openvpn, so IPSec is more preferable.
Cheap and slow SOHO routers generally have worst performance with openvpn that with any other kind of VPN, too.