Multicore PAR2 and OS X.

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shypike
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Re: Multicore PAR2 and OS X.

Post by shypike »

I'm not sure, I've never seen performance issues on my iMac and MacBook.
"Multi-core par2" is disabled because it's only used in Windows.
SABnzbd will use par2-sl from Macpar Deluxe, which normally works quite well.
What does Activity Monitor tell you about its resource load?

redcell
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Re: Multicore PAR2 and OS X.

Post by redcell »

that is awnser is allready in my message, must have edited the message while you posted a reply lol

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shypike
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Re: Multicore PAR2 and OS X.

Post by shypike »

"Extracting" means running unrar to unpack files.
par2 plays no role in this.
So is the performance issue really in "extraction" phase or in the "verify/repair" phase?

redcell
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Re: Multicore PAR2 and OS X.

Post by redcell »

I have tested it for he last couple of days, the problem is during unrar, I even replaced the unrar 5.10 in sabnzbd with the latest version wich is 5.21, but that didn't help...
I also noticed unrar is a 32 bit application, probably also doesn't help speedwise
I also found on the forum several discussions about replacing unrar with 7zip, you also stated in 1 post that in fall 2014 there would be 7zip support in sabnzbd, I guess this is still not the case?
And the problem of switching from unrar to somehting else, because of the integration with sabnzbd related to monitoring the progress during extration
Also the discussion 7zip being open source
How about unar instead of 7zip, the opensource command line extractor for every OS from "The Unarchiver", you are also allready using their par version for osx right? http://unarchiver.c3.cx/commandline
unar also supports more formats then 7zip
wasn't the unarchiver faster in tests then 7zip and unrar?

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shypike
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Re: Multicore PAR2 and OS X.

Post by shypike »

Thanks for your analysis.
7zip will be in the 0.8.0 release, coming out next month (test releases).
The problem is that both 7zip and "the unarchiver" are often behind the real unrar.
Unrar 5 uses a new RAR format and I'm not sure whether it's supported by the others.

Other than that: I cannot reproduce the problematic behavior on either of my Macs.

redcell
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Re: Multicore PAR2 and OS X.

Post by redcell »

I'm guessing you probably have macs with faster hardware and possibly more memory then a macmini and probably quadcores with 8 threads vs the dualcore with 4 threads in a macmini?

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shypike
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Re: Multicore PAR2 and OS X.

Post by shypike »

The trouble is that on both Windows and OSX, software can easily saturate the disk channel.
I can tell you that for unrar the bottleneck is not the CPU but simply the disk channel.
Linux/Unix systems have a tool called ionice that can alleviate this problem, OSX and Windows do not.
In the mean time, I'll check whether unrar has some additional parameters that may lessen the disk load.

redcell
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Re: Multicore PAR2 and OS X.

Post by redcell »


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shypike
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Re: Multicore PAR2 and OS X.

Post by shypike »

Hmm, that's old info. From the time the previous OSX maintainer was still active.
It would be best if the RAR people read that.
But perhaps it can somehow be built into SABnzbd or in a wrapper around unrar.

BTW: the footnotes of setiopolicy_np suggest that there are a lot of caveats.
It also says that it lowers the i/o priority of a process, unrar will not be the same process as SABnzbd (or the wrapper).

redcell
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Re: Multicore PAR2 and OS X.

Post by redcell »

btw do you just download the 32 bit unrar from the rarlabs website and add this to sabnzbd?
I can't remember if the unrar in sabnzbd was 32 bit or 64 bit because I replaced it with a newer version downloaded from the rarlabs website wich was 32 bit
Do you compile unrar yourself or just download it also from their site and add it to sabnzbd?
because I just compiled unrar from source under osx, verry easy btw, only have to enter "make" from terminal, then it compiles as a 64 bit program, but this didn't improve anything btw, but it would be nicer to have a 64 bit unrar instead of 32 bit version bundled with sabnzbd... and compiling only takes a couple of seconds

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shypike
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Re: Multicore PAR2 and OS X.

Post by shypike »

We use unrar's own builds.
As you see no difference between 64bit and 32bit, why bother?
I don't know why rarlabs chooses to deliver only 32bit.

redcell
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Re: Multicore PAR2 and OS X.

Post by redcell »

After alot of research I now know what the problem seems to be and fixed it, posted it here:

https://forums.sabnzbd.org/viewtopic.ph ... 000#p99000

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