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View Full Version : Why is scanning so slo-o-o-o-w?



abr88
2006-04-06, 08:29
Really, I'm curious to know. My computer is a new and quite powerful XP desktop (3.3 ghz I think) -- and Slimserver scanning is the slowest thing I've seen it do. I mean, yes I have 1300+ tracks but it's not like mapping the human genone! Is this being worked on for future software updates? Just curious.

Ben Sandee
2006-04-06, 08:47
On 4/6/06, abr88 <abr88.25umrz1144337401 (AT) no-mx (DOT) forums.slimdevices.com>
wrote:
>
>
> Really, I'm curious to know. My computer is a new and quite powerful XP
> desktop (3.3 ghz I think) -- and Slimserver scanning is the slowest
> thing I've seen it do. I mean, yes I have 1300+ tracks but it's not
> like mapping the human genone! Is this being worked on for future
> software updates? Just curious.


In my experience, speed has improved dramatically on the 6.5 trunk. Work is
definitely being done.

Ben

Mark Lanctot
2006-04-06, 08:48
Well, how slow is slow? Does it finish?

I have 2259 tracks and have just recently started adding artwork. A "clear library and rescan everything" rescan takes me about 90 seconds.

A "look for new and changed music" rescan takes me about 20 seconds.

This is with a P4 2.8 GHz processor running Windows XP SP2.

Yes, it is the slowest thing SlimServer does, but reading 1000+ artist, title and genre tags is not going to be fast. Other programs like Mp3tag and foobar2000 choke on this task as well.

abr88
2006-04-06, 09:46
Yes it finishes, but it takes about 5 minutes (and that's for "look for new", not a complete rescan!)! I wonder why that might be if yours takes only 90 seconds for a full????


Well, how slow is slow? Does it finish?

I have 2259 tracks and have just recently started adding artwork. A "clear library and rescan everything" rescan takes me about 90 seconds.

A "look for new and changed music" rescan takes me about 20 seconds.

This is with a P4 2.8 GHz processor running Windows XP SP2.

Yes, it is the slowest thing SlimServer does, but reading 1000+ artist, title and genre tags is not going to be fast. Other programs like Mp3tag and foobar2000 choke on this task as well.

Siduhe
2006-04-06, 10:16
What format are your tracks in - if MP3, what bitrate and VBR / CBR ?

Is your music on the same box as slimserver is running on, or is it a network share ?

What other plugins do you use (Trackstat, MusicMagic, Moodlogic) ?

All of these factors may affect the time it takes to scan a particular library.

A "look for new" scan still needs to look at every track in the library as I understand it. However, it glosses over the old ones and does a proper scan of the new ones (hence why "look for new" is faster than "full rescan").

5 minutes for an update rescan of a 2259 library is pretty normal IMHO.

sfraser
2006-04-06, 10:56
What format are your tracks in - if MP3, what bitrate and VBR / CBR ?

Is your music on the same box as slimserver is running on, or is it a network share ?

What other plugins do you use (Trackstat, MusicMagic, Moodlogic) ?

All of these factors may affect the time it takes to scan a particular library.

A "look for new" scan still needs to look at every track in the library as I understand it. However, it glosses over the old ones and does a proper scan of the news ones (hence why "look for new" is faster than "full rescan".

5 minutes for an update rescan of a 2259 library is pretty normal IMHO.


I think I'm between 25-35 minutes for 62k songs which are a mix of MP3/FLAC and WAV. The SS is running on the same server and the disk controller is RAID 5 and CPU is and AMD64. I have lots of CPU cycles, and I would expect the RAID to help the read time.

How are other peoples full rescan times?

Siduhe
2006-04-06, 11:07
10-12 minutes for a full rescan of 6,500+ songs (mix of everything from 128mp3 to FLAC, but mostly 320mp3) on a dedicated PC running XP Lite and only Slimserver, MusicIP and related music programs(1gb RAM).

Use MusicMagic enabled, but integrating MM and SS libraries (it seems a lot quicker if I just use MM and don't enter a path for the Music Library in Server Settings).

Mark Lanctot
2006-04-06, 11:17
I think I'm between 25-35 minutes for 62k songs which are a mix of MP3/FLAC and WAV. The SS is running on the same server and the disk controller is RAID 5 and CPU is and AMD64. I have lots of CPU cycles, and I would expect the RAID to help the read time.

How are other peoples full rescan times?

OK, well this got me curious, and those figures were off the top of my head, so I timed it:

"Look for new and changed music": 1:06

"Clear library and rescan everything": 2:39 (so I was a little optimistic!)

But still, based on what it's doing, scanning 2259 items looking for artist, album, title, genre, ReplayGain data, artwork, etc., I don't think this is bad at all. Again, just try Mp3tag or foobar2000 and those take a while to load all this data too.

You can see what's going on if you look at your processor load. A "Look for new" must scan the library looking for recently modified files. It loads my processor up 50-60%.

A "Clear library" scan first conducts a very disk-intensive operation, obviously looking at every file. This loads the processor up 40-50%. Then after a time the disk access ends and the processor loads up 50-60% like in a "Look for new" scan.

Edit: this is using the latest nightly, 2006-04-06.

jonheal
2006-04-06, 11:21
Yes it finishes, but it takes about 5 minutes (and that's for "look for new", not a complete rescan!)! I wonder why that might be if yours takes only 90 seconds for a full????
Five minutes! And you're complaining?! I'd kill for five minutes! I'm runnning Windows 2K on an ancient Athlon XP and my 5000 tracks takes about a half hour!

Actually, I just click the button to rescan, and then go drink beer.

And of course this process beats the crap out of your hard drive. I think those folks that do it daily are nuts. They're just asking for metal filings.

Ben Sandee
2006-04-06, 12:12
On 4/6/06, jonheal <jonheal.25uuvn1144347901 (AT) no-mx (DOT) forums.slimdevices.com>
wrote:
>
>
> abr88 Wrote:
> > Yes it finishes, but it takes about 5 minutes (and that's for "look for
> > new", not a complete rescan!)! I wonder why that might be if yours
> > takes only 90 seconds for a full????
> Five minutes! And you're complaining?! I'd kill for five minutes! I'm
> runnning Windows 2K on an ancient Athlon XP and my 5000 tracks takes
> about a half hour!
>
> Actually, I just click the button to rescan, and then go drink beer.
>
> And of course this process beats the crap out of your hard drive. I
> think those folks that do it daily are nuts. They're just asking for
> metal filings.



All of these times are mostly meaningless unless they also include the
server version (and date for non-final releases like 6.2.2 and 6.5).

Ben

bernt
2006-04-06, 12:40
Have you tried to set priority to background processes?

abr88
2006-04-06, 12:57
What format are your tracks in - if MP3, what bitrate and VBR / CBR ?
- FLAC

Is your music on the same box as slimserver is running on, or is it a network share ?
- Same box

What other plugins do you use (Trackstat, MusicMagic, Moodlogic) ?
- None

All of these factors may affect the time it takes to scan a particular library.

A "look for new" scan still needs to look at every track in the library as I understand it. However, it glosses over the old ones and does a proper scan of the new ones (hence why "look for new" is faster than "full rescan").

5 minutes for an update rescan of a 2259 library is pretty normal IMHO.

- I'm wondering something along these lines (from FAQ) might help - haven't tried it yet...
(Question was: I'm using the SlimServer as a Windows service but the performance isn't good. The music sometimes is choppy and the menus aren't very responsive, especially when it's scanning my music library. What can I do?)
Answer: By default, Windows doesn't give high priority to services and the SlimServer software sometimes needs a fair amount of CPU. To work around this, open your "Control Panels", and then open the "System" control panel. On the "Advanced" tab, find the "Performance" section and click on "Settings". On the "Advanced" tab, choose "Backround Services" under "Processor Scheduling". Click "OK" and the SlimServer software will now get more CPU cycles and perform better.

abr88
2006-04-06, 12:57
What format are your tracks in - if MP3, what bitrate and VBR / CBR ?
- FLAC

Is your music on the same box as slimserver is running on, or is it a network share ?
- Same box

What other plugins do you use (Trackstat, MusicMagic, Moodlogic) ?
- None

All of these factors may affect the time it takes to scan a particular library.

A "look for new" scan still needs to look at every track in the library as I understand it. However, it glosses over the old ones and does a proper scan of the new ones (hence why "look for new" is faster than "full rescan").

5 minutes for an update rescan of a 2259 library is pretty normal IMHO.

- I'm wondering something along these lines (from FAQ) might help - haven't tried it yet...
(Question was: I'm using the SlimServer as a Windows service but the performance isn't good. The music sometimes is choppy and the menus aren't very responsive, especially when it's scanning my music library. What can I do?)
Answer: By default, Windows doesn't give high priority to services and the SlimServer software sometimes needs a fair amount of CPU. To work around this, open your "Control Panels", and then open the "System" control panel. On the "Advanced" tab, find the "Performance" section and click on "Settings". On the "Advanced" tab, choose "Backround Services" under "Processor Scheduling". Click "OK" and the SlimServer software will now get more CPU cycles and perform better.

b1gcountry
2006-04-06, 14:00
One big problem people can have is that DMA is not turned on. This will dramatically slow down any disk intensive tasks. Win2K has a bug where it sometimes will turn this off for you. Not sure about XP. I had this happen to me after I installed a SATA drive into a Win2K machine, and none of the audio would play well. Found out what it was, enabled DMA, and no more skipping.

That said, the rescan function will never be very quick. Every song in your library needs to be accessed by your hard drive. If your disk is fragmented, each fragment of the tag data needs to be accessed. Random Seek Times for hard drives are roughly 10ms, and that's just to position the read head above the data to be read. Reading the data takes time too. The seek overhead for every 100 songs works out to be about a second. So we will never see a 5000 song library rescanned in less than a minute.

If you get real bad rescan times, I'd recommend defragging your library with something like Norton's defrag utility (SpeedDisk?)

HTH
Tom