Slow Downloads on Pi

[Nyhm 1]

So I have a Raspberry Pi running as a torrent box and I use Transmission for that, it auto boots openvpn to connect to the VPN service but I can't seem to get my download speeds to go over 600kb/s and if I run the torrents without the VPN I get speeds around 6/mbs which is where it should be with my 50 megabit connection, any help at all please? I'm using the closest VPN server to me in the USA and have it going through UDP 80, I've tried several different servers and several different ports with no luck =(

[Staff 9767]

Hello!

 

You're probably near to the maximum Raspberry Pi CPU processing power to encrypt/decrypt AES-256-CBC flow (the cipher we use for the Data Channel).

 

Kind regards

[zhang888 1065]

Raspberry Pi 1st gen CPU is not very capable in terms of CPU, which powers the OpenSSL library that is used by OpenVPN.

I never measured it scientifically, but I was never able to get more than 1Mbit on it with OpenVPN in AES256 mode.

[Nyhm 1]

After I posted this I read an article about OpenVPN on a Pi and saw the same thing so I setup a VM running Ubuntu Server and now my speeds are around 900kb/s peak. I've allotted 3 cores and 4gb ram to the VM which I would think would be beyond plenty to max my speed but it won't go over 1mb/s. Any ideas on this? According to speedtest I am getting 8.21 megabit down, but then I go to my normal desktop and clock 52.3 megabit.

 

EDIT: Just wanted to drop in to say that I figured it out, port 80 UDP was not working out that great so I said screw it and tried the 443 UDP again and it's working perfectly! Got 6 megabyte/s on a download which is max for me, thanks for the help!

[bobavpn 0]

HI  i'm having the same problem with a Rpi 2. I'm using  Openmediavault/Transmission/ Openvpn on port 443.
I have forwarded a port through the VPN and i'm connectable.

In Transmission my max speed is 5-6 MegaBytes/s without the VPN.

Once the VPN is on, i reach only 1.8  MegaBytes/s.

I thought also that it came from from Raspberry pi limitation but i'm a bit confused by the load that never reach 2 (Rpi 2 is a quadcore) anc CPU wich is almos under 30%.

Any suggestion ?

[Staff 9767]

HI  i'm having the same problem with a Rpi 2. I'm using  Openmediavault/Transmission/ Openvpn on port 443.

I have forwarded a port through the VPN and i'm connectable.

In Transmission my max speed is 5-6 MegaBytes/s without the VPN.

Once the VPN is on, i reach only 1.8  MegaBytes/s.

I thought also that it came from from Raspberry pi limitation but i'm a bit confused by the load that never reach 2 (Rpi 2 is a quadcore) anc CPU wich is almos under 30%.

Any suggestion ?

 

Hello,

 

that's because currently OpenVPN does not scale on multi-core systems. Each OpenVPN daemon will run only on one core and therefore will load only one core.

 

Kind regards