I run openvpn in tvbox with rk3328 cpu and the speed very fast. Download file 4.5 gb just under 5 minutes.
It is not cpu or openvpn but it is config make the most .
Download file show about 30 MB so upload speed is over 230 Mb . Just check all again .
Here is my server config and that yse the most up to date as show.
server 10.10.90.0 255.255.255.0
mute-replay-warnings
port 7800
tls-version-min "1.2" version
proto tcp4
txqueuelen 4500
tls-cipher TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384
tls-ciphersuites TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256
tls-cipher TLS-ECDHE-ECDSA-WITH-CHACHA20-POLY1305-SHA256:TLS-ECDHE-RSA-WITH-CHACHA20-POLY1305-SHA256:TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256:TLS-ECDHE-RSA-WITH-AES-128-GCM-SHA256
script-security 4
tls-timeout 90
hand-window 900
dev tun2
;dev-node "openvpn"
;ip-win32 manual
;route 10.10.90.0 255.255.255.0 10.10.90.1
push "redirect-gateway autolocal def1 "
push "ping 190"
socket-flags TCP_NODELAY
mute-replay-warnings
push "route-method exe"
push "socket-flags TCP_NODELAY"
remote-cert-eku "TLS Web Client Authentication"
remote-cert-tls client
topology subnet
mode server
hash-size 137552 155372
bcast-buffers 15379870
tcp-queue-limit 10000
tls-server
tun-mtu 48000
mssfix 0
fragment 0
sndbuf 3932106
rcvbuf 3932106
push "sndbuf 3932106"
push "rcvbuf 3932106"
push "route-method exe"
;push "route 192.168.20.0 255.255.255.0 vpn_gateway "
push "route 10.10.90.0 255.255.255.0 "
push "route 192.168.200.0 255.255.255.0"
push "route 192.168.5.0 255.255.255.0 vpn_gateway "
push "route 192.168.1.0 255.255.255.0 vpn_gateway "
push "route 192.168.170.0 255.255.255.0"
push "dhcp-option WINS 192.168.200.1"
push "dhcp-option DNS 192.168.200.1 "
push "dhcp-option NBT 2 "
push "dhcp-option DOMAIN-SEARCH xxx.xx.com"
push "dhcp-option DOMAIN xxx .xx.com"
push "persist-key "
push " persist-tun "
duplicate-cn
client-to-client
keepalive 90 190
persist-key
persist-tun
verb 1
mute 2
ecdh-curve secp521r1
status /var/log/openvpn/openvpn-status.log
log-append /var/log/openvpn.log
;show-engines
;show-curves
;show-tls
;show cipher
;mlock
data-ciphers-fallback AES-256-CBC
auth SHA512
dh none
<ca>
-----BEGIN CERTIFICATE-----
4zEucnlYK7CFpxQ/dosaoMhs39s=
-----END CERTIFICATE-----
</ca>
<cert>
-----BEGIN CERTIFICATE-----
G
-----END CERTIFICATE-----
</cert>
<key>
-----BEGIN EC PRIVATE KEY-----
HevN
-----END EC PRIVATE KEY-----
</key>
<tls-crypt-v2>
-----BEGIN OpenVPN tls-crypt-v2 server key-----
gj
-----END OpenVPN tls-crypt-v2 server key-----
</tls-crypt-v2>