SABnzbd speed nearly always much lower than other clients

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bugmenot
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SABnzbd speed nearly always much lower than other clients

Post by bugmenot »

I am running the win32 distribution and for some reason, I can very rarely get my SABnzbd speed above 212 kps.
I have no idea why.  The only workaround I discovered (and it's definitely a pain to do), is to go into the number of connections and change them from 4 - 6 or vice versa.
Then when SABnzbd starts over the speed will usually bump up to a more respectable 358 kps or above.
The question is why do I need to do this?
I have tried altering the cache size limit, setting bandwith slowdown options (very slightly like .01), and have even upgraded to SABnzbd 3.0 final and nothing changes the speed problem.
I love SABnzbd in every other way but would love to know how to fix this issue which has been going on since 2.5.
Also for some reason, at random times, it on occassion will provide good speeds.  I always copy the nzb's to the monitored directory to start them.
Any help would be greatly appreciated as it is very infuriating.
Thank you in advance.

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shypike
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Re: SABnzbd speed nearly always much lower than other clients

Post by shypike »

You supply very little information on your specific operating system and system speed, memory
firewall software etc.

First, do not enter a bandwidth limit, this will bring the speed down (that its purpose).
Second, the bigger the article cache, the better the performance is (70M is a nice value).

I have tested SAbnzbd on an old Pentium III with 640M memory and Vista Home (yes, this possible).
While this system is not a pleasure to use, SABnzbd still manages to saturate my 2 MBit internet connection
and this gives me 450KByte/sec.

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switch
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Re: SABnzbd speed nearly always much lower than other clients

Post by switch »

Please be aware that the value SABnzbd gives for the speed is an average value, and as such sits between your high and low download speeds. This is the reason it seems to slowly ramp up when starting a download; it is likely going at full speed so give in a few minutes to settle before comparing with other programs.

Always have the maximum number of connections allowed to you to get the most out of your line. The amount of connections you need to get full speed varies depending on your newsgroup and internet providers.

nzb_leecher
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Re: SABnzbd speed nearly always much lower than other clients

Post by nzb_leecher »

do you use an old laptop btw?

DeXeS
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Re: SABnzbd speed nearly always much lower than other clients

Post by DeXeS »

shypike wrote: my 2 MBit internet connection
and this gives me 450KByte/sec.
don't you mean your 4mbit line? 2mbit = max 256kilobytes per second...


For the slowdown factor part, don't use it if you don't want to slow down sab it's bandwidth. Set it to 0.00 for full speed.

what is your maximum downloadspeed and what's the maximum that could b e downloaded from your newsprovider?

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neilt0
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Re: SABnzbd speed nearly always much lower than other clients

Post by neilt0 »

shypike wrote: Second, the bigger the article cache, the better the performance is (70M is a nice value).
That was a good tip. Seems to have sped things up a bit on my NAS. My previous cache was 55MB. 70MB is pushing it, as the NAS only has 128MB RAM.
Where did your cache figure come from, is that calculated or just from trial and error?

BTW, SAB ain't slow. The aforementioned NAS just has a 400MHz ARM9 and 128MB RAM and manages to download at up to 12mbps.

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shypike
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Re: SABnzbd speed nearly always much lower than other clients

Post by shypike »

The article cache should not cause swapping, otherwise it's counterproductive.
As most video post contain 50M RAR files, it's handy that such a file fits completely
in memory. That way the articles don't have to be flushed to disk before assembling
them into a file.

DeXes: yes, I have 4 MBit line, typo.

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neilt0
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Re: SABnzbd speed nearly always much lower than other clients

Post by neilt0 »

shypike wrote: The article cache should not cause swapping, otherwise it's counterproductive.
As most video post contain 50M RAR files, it's handy that such a file fits completely
in memory. That way the articles don't have to be flushed to disk before assembling
them into a file.
With 128MB on a LinkStation, about 100MB of that is usable, so I'm OK.

I set my cache to 55MB before for that reason. Just wondering where 70MB came from...

nzb_leecher
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Re: SABnzbd speed nearly always much lower than other clients

Post by nzb_leecher »

I use 150mb cache just to be sure.

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jcfp
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Re: SABnzbd speed nearly always much lower than other clients

Post by jcfp »

It seems using some margin above the "typical file size" of 50MB makes sense. With the cache size set to just 55MB, that margin would be only 5MB; so basically, you assume that your system will be able to assemble and write the previous 50MB file to disk (thus making the cache memory available for the next file) in less time than is needed to fill up just 5MB with newly downloaded articles.
Such a small amount of margin would almost certainly not be enough for any serious broadband connections.

nzb_leecher
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Re: SABnzbd speed nearly always much lower than other clients

Post by nzb_leecher »

yep hispeed connctions need more ram, but also when the fileserver kicks in for the first 50mb file missing a part. The next 2 x 50mb is already coming so it could be that it is stil busy with the first 50mb. with 1gb on xp i could offer a 150mb cahce with ease.

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