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Slow Download speed using SSL (21 MB/s instead of 60MB/s, QNAP)

Posted: October 7th, 2020, 12:37 am
by 1892
Hey

I've got a problem with my download speed when using SSL on my QNAP nas. When SSL is enabled, my download speed will not go over 21Mb/s but when I disabled it I get my full speed of around 63Mb/s.

What could be the reason for this? I expect some slow down using SSL but not 2/3 of my connection speed. Is there anything I could try to fix this? I'm on the latest version.

Re: Slow Download speed using SSL

Posted: October 7th, 2020, 2:02 am
by sander
Which QNAP model?
Which newsserver? Did you try a different newsserver.

On a modern setup, SSL should not give a slowdown. Some users put in an "easier" SSL Cipher, but I'm not a fan of that, as it more difficult / error prone, and because it should not matter at all in 2020. Anyway, see https://sabnzbd.org/wiki/advanced/ssl-ciphers

Re: Slow Download speed using SSL

Posted: October 7th, 2020, 2:33 pm
by 1892
I use newsgroup ninja and have a TS-251. I'm not sure if a QNAP issue or a Sab configuration issue. I'll try on a different platform and see if speeds remain severely bottle necked.

Edit
Just tried on my surface pro and have the exact same problem. Also tired different SSL ports and different news servers and no change.

Re: Slow Download speed using SSL

Posted: October 7th, 2020, 10:04 pm
by sander
Your CPU (Intel® Celeron® 2.41GHz dual-core processor (burst up to 2.58GHz)) seems good enough.

So I look forward to your other tests.

Re: Slow Download speed using SSL

Posted: October 8th, 2020, 12:51 am
by 1892
After testing on another client I can confirm it is the same issue. I'm starting to suspect it's ISP throttling on certain ports. I'll try with another news service that offers SSL on different ports and update.

Edit

No further forward. I have tried a different usenet provider using SSL on and off for port 443. With it on im getting 21Mb/s and with it off I'm getting 60Mb/s +.

I've tried two different machines, two different download clients, two different usenet providers, different ports and the same ports and still can't figure out why my speed is throttled. Is there anything else I could try? Could my ISP (Virgin Media) be throttling me?

Re: Slow Download speed using SSL

Posted: October 9th, 2020, 1:37 pm
by 1892
Well it turns out it's actually the QNAP is at fault. SSL on CPU usage shoots up to 90%. Off and it remains low. I don't think the CPU is up to it. Time to upgrade I think.

Re: Slow Download speed using SSL (21 MB/s instead of 60MB/s, QNAP TS-251)

Posted: October 9th, 2020, 2:10 pm
by sander
Now I wonder about your CPU:

The "Intel® Celeron® 2.41GHz dual-core processor (burst up to 2.58GHz)" from the QNAP documentation suggests it is the Intel® Celeron® Processor J1800 (from 2013)

In SABnzbd's upper right corner, click on the wrench symbol ("Status and interface options"), then click on first tab Status, and there click on the Refresh Arrow ... at "System performance (Pystone)" what number and CPU name do you set?