dolphs

@gounthar - If you do not mind you cannot reboot ( hangs for the moment ) what about the orangepi Lite 2? 
It can do 1,8GHz BUT H6 SoC is still in developement (WIP), it is half the price of a RockPi4, model A 1GB (RK3399).
had promising results using a OPiOnePlus with ovpn ( near 200Mbit maybe more as my upload is CAPped ).
A +/- 12Mbit stream resulted in 40% CPU usage, pushing it to the max ( iperf single/ multiple threads ) got it easily to 1,8GHz : my findings, incl temp increase, can be found here 
Anyway the board has BT, both WiFi and LAN gigabit - but as mentioned DEV image ( kernel 5.x ) needs to be build to have it " somewhat stable " , for VPN (LAN) it works at least.
hope this helps

Please refer to this topic rgd issue 1)
Also to create some more awareness I contacted "Allwinner Customer Service Team" recently and they made this a Xunlong issue,
their response: " After a short discussion internally, we suggest you contact Xunlong for clarification.
Let's hope for a satisfactory solution, little/ some hope this can be increased as Xunlog is partnering with armbian ... ...
 
let's keep fingers crossed...

omg, let's bump dev to 5.05 ( current kernel ) and build a fresh debian image.
Mr martinayotte, I should like to express my respect to you for your work!
Will check back later as duty calls ( cooking for the wife ;-) )

hi running armbian ( kernel 4.14 ) and ovpn 2.4.6 and both nanopi neo2 boards.
ovpn is configured with cipher AES-128-CBC and auth SHA256, following results can be seen:

 
top - 04:53:47 up 26 days, 11:42,  2 users,  load average: 0.16, 0.16, 0.09 Tasks: 102 total,   2 running,  57 sleeping,   0 stopped,   0 zombie %Cpu0  :  1.0 us,  1.0 sy,  0.0 ni, 98.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st %Cpu1  :  1.0 us,  2.0 sy,  0.0 ni, 97.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st %Cpu2  : 20.7 us, 30.1 sy,  0.0 ni, 43.5 id,  0.0 wa,  0.0 hi,  5.7 si,  0.0 st %Cpu3  :  0.3 us,  0.3 sy,  0.0 ni, 99.0 id,  0.0 wa,  0.0 hi,  0.3 si,  0.0 st KiB Mem :   494152 total,   128980 free,    92528 used,   272644 buff/cache KiB Swap:   247072 total,   229664 free,    17408 used.   382416 avail Mem   PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND  1191 root      20   0   10180   6132   5324 R  59.1  1.2 137:16.90 openvpn  
and following with single thread " iperf3 -4 -V -c 192.168.10.2 -t 60 -b 0 -P 1 "
 
iperf 3.1.3 Linux vpn01 4.14.70-sunxi64 #274 SMP Wed Sep 19 12:09:30 CEST 2018 aarch64 Time: Sun, 09 Dec 2018 02:53:07 GMT Connecting to host 192.168.10.2, port 5201       Cookie: vpn01.1544323987.071807.somewhat       TCP MSS: 1276 (default) [  4] local 10.8.0.2 port 63472 connected to 192.168.10.2 port 5201 Starting Test: protocol: TCP, 1 streams, 131072 byte blocks, omitting 0 seconds, 60 second test [ ID] Interval           Transfer     Bandwidth       Retr  Cwnd [  4]   0.00-1.00   sec  9.07 MBytes  75.9 Mbits/sec  199   1.24 MBytes [  4]   1.00-2.00   sec  8.75 MBytes  73.4 Mbits/sec  166   1.09 MBytes [  4]   2.00-3.00   sec  12.5 MBytes   105 Mbits/sec    0   1.35 MBytes [  4]   3.00-4.00   sec  7.50 MBytes  62.9 Mbits/sec    0   1.36 MBytes [  4]   4.00-5.00   sec  7.50 MBytes  62.9 Mbits/sec   54   1.22 MBytes [  4]   5.00-6.00   sec  8.75 MBytes  73.4 Mbits/sec    0   1.22 MBytes [  4]   6.00-7.00   sec  7.50 MBytes  62.8 Mbits/sec    0   1.24 MBytes [  4]   7.00-8.00   sec  8.75 MBytes  73.5 Mbits/sec    0   1.16 MBytes [  4]   8.00-9.00   sec  8.75 MBytes  73.3 Mbits/sec    0   1.21 MBytes [  4]   9.00-10.00  sec  11.2 MBytes  94.4 Mbits/sec    0   1.41 MBytes [  4]  10.00-11.00  sec  8.75 MBytes  73.4 Mbits/sec    3   1.59 MBytes [  4]  11.00-12.00  sec  7.50 MBytes  63.0 Mbits/sec   46   1.58 MBytes [  4]  12.00-13.00  sec  10.0 MBytes  83.9 Mbits/sec    0   1.27 MBytes [  4]  13.00-14.00  sec  7.50 MBytes  62.9 Mbits/sec   25   1.17 MBytes [  4]  14.00-15.00  sec  11.2 MBytes  94.4 Mbits/sec    0   1.40 MBytes [  4]  15.00-16.00  sec  11.2 MBytes  94.4 Mbits/sec   15    616 KBytes [  4]  16.00-17.00  sec  6.25 MBytes  52.4 Mbits/sec    9   1.25 MBytes [  4]  17.00-18.00  sec  8.75 MBytes  73.4 Mbits/sec  252   1.15 MBytes [  4]  18.00-19.00  sec  7.50 MBytes  62.9 Mbits/sec    0   1.24 MBytes [  4]  19.00-20.00  sec  10.0 MBytes  83.8 Mbits/sec   29    684 KBytes [  4]  20.00-21.00  sec  7.50 MBytes  62.9 Mbits/sec    0   1.24 MBytes [  4]  21.00-22.00  sec  7.50 MBytes  62.9 Mbits/sec  194   1.26 MBytes [  4]  22.00-23.00  sec  8.75 MBytes  73.4 Mbits/sec    0   1.25 MBytes [  4]  23.00-24.00  sec  7.50 MBytes  62.9 Mbits/sec    0   1.16 MBytes [  4]  24.00-25.00  sec  12.5 MBytes   105 Mbits/sec    0   1.43 MBytes [  4]  25.00-26.00  sec  6.25 MBytes  52.4 Mbits/sec   46   1.42 MBytes [  4]  26.00-27.00  sec  8.75 MBytes  73.4 Mbits/sec    0   1.40 MBytes [  4]  27.00-28.00  sec  8.75 MBytes  73.4 Mbits/sec   18   1.24 MBytes [  4]  28.00-29.00  sec  8.75 MBytes  73.4 Mbits/sec    0   1.23 MBytes [  4]  29.00-30.00  sec  10.0 MBytes  83.9 Mbits/sec    0   1.37 MBytes [  4]  30.00-31.00  sec  7.50 MBytes  62.9 Mbits/sec    0   1.26 MBytes [  4]  31.00-32.00  sec  8.75 MBytes  73.4 Mbits/sec   64   1.15 MBytes [  4]  32.00-33.00  sec  8.75 MBytes  73.4 Mbits/sec    0   1.16 MBytes [  4]  33.00-34.00  sec  10.0 MBytes  83.9 Mbits/sec    0   1.34 MBytes [  4]  34.00-35.00  sec  8.75 MBytes  73.4 Mbits/sec    0   1.34 MBytes [  4]  35.00-36.00  sec  8.75 MBytes  73.4 Mbits/sec    0   1.26 MBytes [  4]  36.00-37.00  sec  8.75 MBytes  73.4 Mbits/sec    0   1.29 MBytes [  4]  37.00-38.00  sec  8.75 MBytes  73.4 Mbits/sec    0   1.25 MBytes [  4]  38.00-39.00  sec  7.50 MBytes  62.9 Mbits/sec    0   1.25 MBytes [  4]  39.00-40.00  sec  10.0 MBytes  83.8 Mbits/sec    0   1.16 MBytes [  4]  40.00-41.00  sec  11.2 MBytes  94.4 Mbits/sec    0   1.37 MBytes [  4]  41.00-42.00  sec  10.0 MBytes  83.9 Mbits/sec    0   1.38 MBytes [  4]  42.00-43.00  sec  7.50 MBytes  63.0 Mbits/sec   79   1.07 MBytes [  4]  43.00-44.00  sec  8.75 MBytes  73.4 Mbits/sec   34    728 KBytes [  4]  44.00-45.00  sec  7.50 MBytes  62.9 Mbits/sec   99   1.38 MBytes [  4]  45.00-46.00  sec  7.50 MBytes  62.9 Mbits/sec  200   1.38 MBytes [  4]  46.00-47.00  sec  8.75 MBytes  73.4 Mbits/sec   62   1.21 MBytes [  4]  47.00-48.00  sec  7.50 MBytes  62.9 Mbits/sec   22   1.26 MBytes [  4]  48.00-49.00  sec  8.75 MBytes  73.5 Mbits/sec    0   1.33 MBytes [  4]  49.00-50.00  sec  8.75 MBytes  73.4 Mbits/sec    5   1.23 MBytes [  4]  50.00-51.00  sec  7.50 MBytes  62.8 Mbits/sec    0   1.25 MBytes [  4]  51.00-52.00  sec  10.0 MBytes  84.0 Mbits/sec    0   1.30 MBytes [  4]  52.00-53.00  sec  7.50 MBytes  62.9 Mbits/sec    0   1.29 MBytes [  4]  53.00-54.00  sec  8.75 MBytes  73.4 Mbits/sec    4   1.26 MBytes [  4]  54.00-55.00  sec  7.50 MBytes  62.9 Mbits/sec    0   1.24 MBytes [  4]  55.00-56.00  sec  8.75 MBytes  73.4 Mbits/sec    0   1.23 MBytes [  4]  56.00-57.00  sec  7.50 MBytes  62.9 Mbits/sec    0   1.19 MBytes [  4]  57.00-58.00  sec  10.0 MBytes  83.9 Mbits/sec    0   1.23 MBytes [  4]  58.00-59.00  sec  7.50 MBytes  62.9 Mbits/sec    0   1.21 MBytes [  4]  59.00-60.00  sec  6.25 MBytes  52.4 Mbits/sec    0   1.24 MBytes - - - - - - - - - - - - - - - - - - - - - - - - - Test Complete. Summary Results: [ ID] Interval           Transfer     Bandwidth       Retr [  4]   0.00-60.00  sec   520 MBytes  72.7 Mbits/sec  1625             sender [  4]   0.00-60.00  sec   514 MBytes  71.8 Mbits/sec                  receiver CPU Utilization: local/sender 1.5% (0.1%u/1.3%s), remote/receiver 3.5% (0.4%u/3.2%s) iperf Done.  
 
also did not tweak kernel settings too much atm - both ends read:
net.core.default_qdisc = fq_codel net.core.netdev_max_backlog = 1024 net.core.rmem_max = 33554432 net.core.wmem_max = 33554432 net.ipv4.tcp_rmem = 4096 87380 33554432 net.ipv4.tcp_wmem = 4096 87380 33554432 net.ipv4.tcp_congestion_control = bbr # RETEST westwood OR cubic net.ipv4.tcp_max_syn_backlog = 1024 net.ipv4.tcp_slow_start_after_idle = 0 net.ipv4.tcp_no_metrics_save = 0 net.ipv4.ip_local_port_range = 9000 65535  
If you want a cheap and low wattage VPN consider H5 boards ( eg nanopi neo2 or orange pi zero plus2 ) that should handle proper TV streaming (15-20Mbit) over ovpn this is your option.
If speed will be most important consider other platforms, I'm currently looking in to the ASRock J4005B-ITX and should do 300Mbit ...