Troubleshooting Speed

[howiwef938]

Have just moved to a different seedbox provider and am looking for some help (I was seeing much greater speeds on previous host with a vanilla config).
I can’t get a sustained speed much above 50 MB/s and it seems to fluctuate anywhere as low as 20 MB/s to 60 MB/s and not much higher. In some downloads I see the speed graph spike at the top and then straight back down to the bottom like it’s bursting. I’ve performed a Speedtest frequently and I see both the bandwidth change often (lowest I have spotted is around 80 MB/s and the highest right now is 152 MB/s. The folder speeds fluctuate around the actual reported download speed so my thought is that the bottleneck is the disk speeds (it’s a shared server).

I have two providers, both are connected to the EU servers (seedbox is in AMS). Vipernews and Newshosting. Both are set to 0 priority. Both providers are set to 30 connections each. Originally were set to 20 but the speed would hardly ever peak over 50 MB/s. Pushing them to 30 seemed to hit a more stable 60MB/s.

Stats;

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Used cache
0 B (0 articles)
System performance (Pystone)
70287 Intel(R) Xeon(R) CPU E5-2…
Download folder speed
46.3 MB/s ()
Complete folder speed
61.9 MB/s ()
Internet Bandwidth
129.1 MB/s (1032.8 Mbps)

1000MB Test;

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Download
Downloaded in 19 seconds at an average of 52.4 MB/s

Is there anything we can look at tweaking to gain more out of this or is it more of an issue with the disk usage being a shared resource and it’s been capped to that speed somewhere else to keep everyone else on the server in the same situation?

[sander]

I would say disk speed it too low ... that looks like HDD speeds, not SSD nor NVMe.

[howiwef938]

Thanks, My seedbox has told me that that speed is more than half the overall disk input output speed and is more than reasonable. They said "Sabnzbd has tuning imposed but rather at resource level". Then they also said that their NVMe servers have the same "limits" applied and that NZBGET is a better client because of lower resources.

Based on this - it seems pretty obvious that the issue is the disk speed provided by the server and nothing else. What is the tuning they are talking about, is there anything we can do? What would the frequent speed drops I see in downloads be caused by? Other users on the same server hammering the disk so that the write speed drops severely?

[sander]

Have just moved to a different seedbox provider and am looking for some help (I was seeing much greater speeds on previous host with a vanilla config).

Read back what you wrote ... and consider going back?

[howiwef938]

and consider going back?

Sadly they have shut down recently. So I just wanted to see if there was anything further I could tweak before getting a refund.

[sander]

I see. Out of curiosity: which seedbox provider is this? And do they say anything about the type of disk?

If the underlying hardware is not stable-speedy, SABnzbd (or any software) cannot make that stable or speedy.

Just checking:
- you measure the CPU & Disk perf while SAB is *not* downloading, I hope?
- what download speed do you get with Wrench -> Test Download 1000 MB?

[howiwef938]

Thanks for the reply! New provider is USB and the server is listed as a non ssd/NVMe.

Yes the tests were all performed while sab was sitting idle. I just performed another 3x tests one minute apart.

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Used cache0 B (0 articles)
System performance (Pystone) 69221|70742|64251
Intel(R) Xeon(R) CPU E5-2…
Download folder speed 77.2 MB/s|92.3 MB/s|52.1 MB/s 
Complete folder speed 88.8 MB/s|72.2 MB/s|58.7 MB/s
Internet Bandwidth 67.7 MB/s (541.6 Mbps)|132.1 MB/s  (1056.8 Mbps)|97 MB/s  (776 Mbps)

For the test download;

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Sourcehttps://sabnzbd.org/tests/test_download_1000MB.nzb
DownloadDownloaded in 19 seconds at an average of 52.5 MB/s
Age: 42d
Serversnews.newshosting.com=647.4 MB, news.vipernews.com=374.1 MB

I tried this also with just one server at a time and the results were very close (although both bursted at around a 70-80MB/s for a second and then came straight back down to the low 50's.
NH only =Downloaded in 18 seconds at an average of 56.1 MB/s
VN only = Downloaded in 21 seconds at an average of 48.7 MB/s

[sander]

With those not-too-great CPU and DIsk speed, I would say the resulting download speeds (48 - 56 MB/s) are not too bad.

But, as said, for line speed 100 MB/s you need better CPU and Disk speeds.