Cubieboard2 openVPN network speed

[gevero 3]

Hi

 

I am using a Cubieboard2 with Arch Arm as a server, along with openVPN. Cubieboard2 is a pretty fast dual core armv7 box (more than twice faster than the Rpi, for instance) When I am connected directly to the internet performing a speedtest, I can max out my FASTWEB connection at  ~ 7.4MB/s (60Mbit). If I use openvPN though I get 1.2MB/s (10mbit) at most, with sporadic bursts at 1.4/1.5 MB/s . If I try the same from my laptop, I have only a small penalty in speed, going around 5.0/6.0 MB/s.

My first guess was a CPU bottleneck as for my old Raspberry Pi, nevertheless openvpn cpu usage seldom goes above 30% for one single core. I tried to toy with the mmsfix parameter and to change server, but the 1.4/1.5MB/s barrier seems unbreakable, and the cpu load is always below 40%. My estimated was that I could get speed between 2 and 3MB/s. What could be the reason of this kind of performance?

 

Best Regards

[s2u9p7aq5wciel7ko8o07 1]

I remember that there are tests that you can perform on the board which output the total speed for the various encryptions algorithms. Something to do with openssl. Other than that are you sure that it is not something else that is bottlenecking the connection? Is the cubieboard using wifi or wired?

 

Or lastly i think that AirVPN uses AES for the encryption and is it posible that the cpu used on the cubieboard does not have the instruction set for AES.

[GMPSQ 29]

I have had similar issues, open a support ticket maybe.

I was able to increase performance by about 20% by using port 53 UDP and choosing a geographically closer server. It still isn't what I was hoping for yet, but with more research and tinkering we may be able to get more speed.

[gevero 3]

Hi Guys

 

Thanks for your answers but:

 

1. Cubieboard is wired, and when running without openvnp i max out my 60Mbit connection
2. Server is no issue... when i run openvpn with the same server but from my laptop, i get at lest 40Mbit, which would be more than enough
3. UDP port is not an issue: i tried more than one, and nothing changes

At this point i suspect that this as something to do with the interaction between Arch ARM and openvpn. Any guess?

 

Thanks a lot!!!

[Staff 9973]

@gevero

 

Hello!

 

Various ARM processors are not probably able to decrypt/encrypt more than 10-11 Mbit/s of AES-256-CBC throughput, which is very near to the performance you already experience.

 

Kind regards

[gevero 3]

I would like give an update on the subject:

 

When torrenting I could get speeds up to 2.5MB/s in download and 0.5MB/s in upload, i.e 3MB/s globally with 100% CPU load from openvpn: close to what i was expecting. Anyway I seem unable to obtain such speeds with a simple wget download from very fast servers...I am pluzzled... Any thoughts?

 

Best regards