SABnzbd Forums

After upgrading to 300 mbit cable from 200 mbit ,I noticed that my download was fluctuating between 14 ~ 35 MB/sec.
Ruling out all the other options (provider, news server) I decided to change the following two settings under General/Tuning:
Maximum line speed (34M)
Percentage of line speed (100)

With the above setting I finally get a stable download of 34 MB/sec.
On my previous speed (200 mbit) I had both of these settings empty and speed was always maxed out.

Can anybody explain this behavior?

ps I should be able to get a little better download speed (around 36~40 MB/sec) but when raising the Maximum line speed to 35m I get the fluctuating speeds again.

update: Something is not working like it should, now I have speeds again between 10 and 25 MB/sec. When trying the same NZB with NZBget I'm getting speeds between 34 and 38 MB/sec.

Yes, SABnzbd is the problem. Specifically the decoder of the articles.
After an article is downloaded, it needs to be decoded to become part of the final file. At a certain point decoding just cannot keep up with the downloading and SABnzbd will throttle the download speed for a few seconds, this is the behavior you're seeing. It will go up and down and up and down. Seems 34MB/s was the balance for your setup.
Some downloads have different article sizes, so the decoder might be slower/faster on some downloads.

We have some improvements for SABnzbd 1.1.0 which will imrpove speeds, but might still be a few months out for final release. At these speeds NZBGet programming language (C++) just outperforms Python when doing the decoding and assembling. We try to make the best of it!

Thanks, would a faster CPU help? Using a 7 year old AMD Phenom II X4.

It would, but for now nzbget might be the better solution. Until we can really push more out of Sabnzbd.

Did some tests but SABnzbd 1.1.0 bèta 1 download seems to be on par with nzbget now! (stable around 36mb/sec).
Thanks!!