Optimizing for slow devices?

[iSteven]

Hi forum

I recently purchased a Synology DS212+ storage box. Installing and configuring SABnzbd was a breeze, but I'm still having some performance issues. I'm only reaching about 3MB/s download speeds, which is about half the speed that I used to get on my windows-based, much more powerful laptop.

Basically, as soon as I begin a new download, my resource monitor displays 100% CPU usage. Most of which is caused by the python package provided by syno community. I guess this is creating a bottleneck effect, forcing SABnzbd to download at a slower pace.

I googled around for a few hours, but there doesn't seem to be much concrete information on this subject. Some suggested installing the C based yenc package (I believe it's called py25-yenc), which I did through ipkg. I didn't notice any immediate download speed increase though. I've also changed the maximum amount of connections down from 50 to 10, but still no dice. I connect to my usenet provider (newsdemon) using SSL encrypted connections on port 563. I don't think my server settings are the problem though, my computer doesn't have any problem downloading.

Is there anything I should be doing differently? All suggestions are welcome.
Steven

Code: Select all

Version: 0.7.1-2
OS: N/A
Install-type: linux repository (http://www.synocommunity.com)
Firewall Software: None
Are you using IPV6?: No
Is the issue reproducible?: Yes

[shypike]

The only extra thing you can do is set an article cache in Config->General.
Your system needs to have plenty if memory (at least 512M)
and the influence is different per system.
Set it to something like 128M.

[iSteven]

Thanks for the suggestion.

What is the default cache size? Or does it not use a cache unless explicitly set? The web interface doesn't really show.

[shypike]

For Linux systems, there's no default, so empty box means: no cache.

[iSteven]

Alright thank you. At the end of the day, none of these tweaks really seem to do anything on a synology NAS. I guess that a fast CPU is a minimum requirement before you can start fine-tuning things.

[shypike]

I'm afraid you're right about that.
CPU usage is SABnzbd's weak spot.

[bbaraniec]

I'm running SAB on linux box with Intel Dual Core 2,6Ghz and when I leave SAB "unleashed" CPU usage goes over 50%. My connection is 35Mbit/s and if I reduce the speed in SAB to 4096kbit/s (4MB/s) which is almost my max speed CPU usage drops to 15-20ish %. Correct me if I'm wrong but Python is not using dual cores or?

[shypike]

As far as I know, Python is single-core.
Its multi-threading architecture doesn't make the OS use multiple cores for it.

[jcfp]

I'm running SAB on linux box with Intel Dual Core 2,6Ghz and when I leave SAB "unleashed" CPU usage goes over 50%.

Depends on your source for that percentage. Some utilities in linux, such as ps and top, present cpu usage of processes as a percentage of single core performance, without division by the total number of cpu cores available. For example, on a dual core system, with a single core application maxing out one of the cores (cpuburn style), that application's cpu usage would be indicated as ~100% in such utilities although it represents only half the cpu power available.