SABnzbd Forums

Hi There,

I have a 50Mb downstream and 1.5Mb upstream connection (i know  ) - when downloading, sabnzb doesn't seem to be able to get above 25-30Mb/sec - after scratching my head as to why for a while, I noticed that the upsteam on the connection was getting saturated at 1.5Mb/sec, which explains why the downloads wouldn't go any higher.

Interestingly enough, newsbin is able to manage a full 50Mb/s - and while downloading at this speed the upstream usage generally hovers around the 1Mb/s mark. Any idea's why sab's upsteam usage is notably higher? I'm using giganews with SSL. I've tried varying the number of connections with no success.

Is there anything I could adjust in sabnzb that might help, or should I perhaps be looking at TCP tuning in the OS?

It's worth noting that my sabnzb pc is freebsd, and the newsbin pc windows 7.

The main thing that SABnzbd sends upstream are article numbers.
Are you using the same amount of connections?

Just tried on Linux, set the speed limit all the way down to 50 mbit. While downloading from 2 different servers, 12 connections total, upload was around 300 kbit (used iftop to check). To get the upload to average 1 Mbit, I had to set the download speed cap well north of 100 mbit.

Don't know if the specific download matters, i.e. like when some uploader made the file parts real small, that might need more upload?

Article identifiers are fairly equal in size.
Smaller articles, mean more article requests.
But this would vary per NZB and the same NZB should have equal overhead on every client.
The only other factor increasing the upstream bandwidth would be frequent retries.
Like when you have a normal and a backup server and the normal server doesn't have the articles.
This would double the upstream bandwidth.

Hi There,

Thanks for your replies - appreciate your input.

The upstream usage seems pretty consistent over multiple NZB files - I've tried less and more connections than newsbin, doesn't seem to make too much difference. I've also tried turning SSL off, again, no change.

Nothing complicated like fill servers, only one server set up - giganews.

I'm going to try an install of the latest on windows, see how that performs. Figure there must be something really funky with my network setup somewhere!

so, the windows box performs identically to newsbin - downloads at close to 50Mb/s and uploads around 1Mb/sec

First I'm going to try updating the freebsd box to 0.5.6, then I'll look at network tuning. Anyone have any ideas where to start?

All I can say is I have a similar setup (sabnzbd/freebsd) and I can go as high as 30Mb with around 300~400kb/s.
My link is 30Mb, so I cannot go higher than that.
Linux performs equal to freebsd as I am currently testing on fedora 14.
Cheers

jcfp wrote: Just tried on Linux, set the speed limit all the way down to 50 mbit. While downloading from 2 different servers, 12 connections total, upload was around 300 kbit (used iftop to check).

Completely offtopic: tried iftop, and what a cool tool. Apart from my own traffic per site, I see a lot of Apple devices in my iftop overview ... I'm on a coffeecompany hotspot ... zeroconf at work, I guess ... 

And now ontopic:

with only SAB using the network, I had iftop running, and here are the results:
So my upstream:downstream ration is 1:53 (cumm) and 1:47 (peak). So in my case (ADSL) my downstream (11+ Mbps) is the bottleneck, not my upstream (1 Mbps).

so, I solved this eventually - after messing around with various test's on clean installs and updating sabnzbd, I slowly ruled out hardware and other considerations until i found a few weird kernel network tuning parameters that I'd tried to use to speed up samba. Took them out, and walla, identical performance to windows/my clean freebsd test installs. Wish I'd remembered those first!

currently :

TX:             cumm:  44.6MB   peak:   0.99Mb
RX:                    1.94GB           42.7Mb


so not as good as others - can't get anywhere near 300kbps US at 50Mb/s DS, but it's working well enough for me now to stop worrying about it. In fairness there's also some background traffic in above stats - mainly just an SSH session and a sabnzbd webif open.

Thanks to all who took the time to reply - without your stat's I would probably have never gathered enough motivation to try and fix the issue. Owe you all some beers.

As said, mine varies a bit between 300 and 400Kbps depending on the DS speed which can go as high as 30Mbps.
But usually it stays around 350kbps and 25Mbps, which means theoretically it should raise to 700kbps if my line could go as high as 50Mbps.
As said, all theory.