Open VPN ASIC/FPGA?
Is there such thing as an Open VPN ASIC/FPGA that can run Open VPN better then a nic CPU? Something I can plug into either a SATA, PCI or M.2 port?
Not really. Or at least nothing specific to OpenVPN.
You can use something that OpenSSL can use directly, like AES-NI, or something that can tie into the crypto framework, like CESA. Both those will accelerate OpenSSL and hence OpenVPN but total throughput in OpenVPN is still limited by context switching (between kernel and user modes).