iTunes jerks like nothing else!?!?!
 

Hey there.

recently had to reformat and reinstall everything. Since I've done that, iTunes becomes really jerky when I'm uploading files to an online server. Happens when I'm uploading via dreamweaver, transmit, and even in Safari when I'm uploading music/videos to my band's myspace page. Really suck's when I'm uploading larger files for a few minutes and I get jerky, almost static-y, playback on iTunes.This never happened before the big reformat.

Some details:
Dual 1GHz G4, OSX 10.4.6, iTunes v6.0.4(3), Safari v2.0.3 (417.9.2).
My music is stored on a separate internal drive to apps and the OS. According to Activity Monitor, iTunes seems to use an average of 5-9% CPU at any given time. When I upload using other apps, nothing seems to jump up out of the ordinary and hog up all the CPU cycles (usually 20% or so for front-most app) so I don't think it's a CPU issue.

Any ideas?

_thanks in advance
_bkpr

When you are looking at the active threads in Activity Monitor, do you have it set to "All Processes"? Are you sorting by %CPU, so that something unexpected down the list that might be taking heinous amounts of CPU time can jump to the top?

Trevor

It sounds almost certainly to be related to the fact that your upload is accessing files on the disk that iTunes is also reading from. I.e. that the problem is a disk problem.
Maybe its a leftover from whatever problem caused you to have to reformat.
What was your precious problem that caused you to do that?

Maybe the drive is going bad. What does Disk Utility say for its SMART status?

Hi . Thanks for you quick reply.

Trevor - Yes I have all processes set in Activity monitor, as well as sorting by CPU.

Hayne - The files I'm uploading are from my first drive (start up), the music file iTunes is playing are on a second drive.

Not 100% sure about what went wrong with my startup drive, but many of my apps suddenly failed to open and neither Disk Utility or Disk Warrior could repair the disk, so I erased and reformatted.

Disk Utily reports that all three drives on my machine say SMART status verified.


I was thinking it could be some memory setting in iTunes/safari/Finder that I used to have set a certain way, but since reformatting haven't set it the same way. Could this be a possible cause? Also, noticed that it's definately a stop/start jerking in iTunes, as opposed to just the sound cutting out. Thought I'd mention that.

So, just to be sure I understand correctly, you have 3 separate disk drives in your Mac - not just 3 partitions on one drive - is that right?

1) You should do a "Verify Disk" from Disk Utility on all of your drives.

2) Launch the "Console" application (under /Applications/Utilities) and look for relevant error messages at the time when you notice the problem. Note that messages are labeled with the date & time so you can use that to locate the part of the log to look at. Copy & paste the relevant messages back here so we can see them.
Be sure to look at system.log as well as console.log (Use the "Logs" button (top-left) to see the various logs available - note that you will probably need to be an "admin" user to see the system.log)

hi Hayne.

Yes, I have three separate disks, not separate partitions.
Disk Utility initially reported 'illegal name' (x2) on my starup disk, and told me it needed repair. The other disks were ok. Repaired my startup disk, but the problem still persists.

Tests: opened Safari into myspace.com and got ready to upload my file. Started iTunes, played perfectly. As soon as I click 'upload video', it starts jerking about. Console reported this (in system.log):

===== Sunday, 28 May 2006 2:20:46 AM Australia/Melbourne =====
May 28 02:20:57 bkprG4 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/Metadata.framework/Versions/A/Support/mdimportserver: _TIFFVSetField: tiff data provider: Invalid tag "Copyright" (not supported by codec).\n
May 28 02:20:58 bkprG4 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/Metadata.framework/Versions/A/Support/mdimportserver: _TIFFVSetField: tiff data provider: Invalid tag "Copyright" (not supported by codec).\n
May 28 02:20:58 bkprG4 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/Metadata.framework/Versions/A/Support/mdimportserver: _TIFFVSetField: tiff data provider: Invalid tag "Copyright" (not supported by codec).\n
May 28 02:20:58 bkprG4 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/Metadata.framework/Versions/A/Support/mdimportserver: _TIFFVSetField: tiff data provider: Invalid tag "Copyright" (not supported by codec).\n
May 28 02:21:42 bkprG4 kernel[0]: IOAudioStream[0x3da5900]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (469,ffb)->(46d,1b1f).
May 28 02:21:42 bkprG4 kernel[0]: IOAudioStream[0x3da5900]::clipIfNecessary() - adjusting clipped position to (46d,ffb)
May 28 02:21:45 bkprG4 kernel[0]: IOAudioStream[0x3da5900]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (47f,29f8)->(485,15da).
May 28 02:21:45 bkprG4 kernel[0]: IOAudioStream[0x3da5900]::clipIfNecessary() - adjusting clipped position to (484,29f8)
May 28 02:21:58 bkprG4 kernel[0]: IOAudioStream[0x3da5900]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (4c7,2bfd)->(4c9,1524).
May 28 02:21:58 bkprG4 kernel[0]: IOAudioStream[0x3da5900]::clipIfNecessary() - adjusting clipped position to (4c8,2bfd)
May 28 02:22:05 bkprG4 kernel[0]: IOAudioStream[0x3da5900]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (4ef,27fe)->(4f4,1842).
May 28 02:22:05 bkprG4 kernel[0]: IOAudioStream[0x3da5900]::clipIfNecessary() - adjusting clipped position to (4f3,27fe)
May 28 02:22:09 bkprG4 kernel[0]: IOAudioStream[0x3da5900]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (508,13fd)->(50c,192c).
May 28 02:22:09 bkprG4 kernel[0]: IOAudioStream[0x3da5900]::clipIfNecessary() - adjusting clipped position to (50c,13fd)
May 28 02:22:10 bkprG4 kernel[0]: IOAudioStream[0x3da5900]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (510,1627)->(515,169c).
May 28 02:22:10 bkprG4 kernel[0]: IOAudioStream[0x3da5900]::clipIfNecessary() - adjusting clipped position to (515,1627)

I also noticed that there were a couple of really small jumps in playback when I was navigating to the upload page, i.e. loading the webpages. But, it's a billion times worse when uploading.

Hope this stuff make sense to you! Thanks for taking the time to check it out for me!

The only thing I notice is the reference in the log to 'mdimportserver' - I think that is something related to Spotlight. But why it would be getting info about a TIFF file at that time I don't know.

Those bits about the tif, i.e. before the "bkprG4 kernel[0]: IOAudioStream[0x3da5900]" parts, was when I was navigating to the upload page. Once I got there and clicked 'upload', then the IOAudioStream shenanigans ensue.

You mentioned spotlight, is there a way I can disable spotlight temporarily to see if that has any effect. I suspect it won't but this thing drives me up the wall so much I'm desperate to get to the bottom of it!

I just realised that I've changed my wireless setup at home not long after the reformatting. I was running an D-link ADSL modem, into an airport base station, transmitting to my G4. My new setup consists of a Netgear, wireless Modem?router combo, transmitting to my G4.

Tonight, I'll try run it directly INTO the router with an ethernet cable, to see if that makes any difference... will keep you posted.

I'm not up on Spotlight stuff, but I think there have been some articles on the main macosxhints site about disabling Spotlight.

Is it possible that iTunes is trying to transmit over the wireless connection to speakers? That normally only happens with Airport Express, so I guess not.

Here's some info I've gathered:
1. Disabling Spotlight has no effect on the situation.
2. Reinstalling iTunes has no effect on the situation.
3. When using my iBook (not the desktop G4) to upload files while iTunes is playing, there is no issue. iBook is running 10.3.9 though...
4. When mounting any of the three Desktop machine drives onto the iBook, and copying files across, the Desktop copy of iTunes jerks wildly. This led me to believe it's a network issue, but...
5. when mounting the iBook's only drive onto the Desktop machine, and copying files, (i.e.: copying files the OTHER WAY) there is no iTunes issue (and the console doesn't report anything happening).

One might conclude that any OUTGOING transfer (uploading through safari/Dreamweaver, dragging files from one of the desktop drives) makes iTunes jerk around, but INCOMING activity doesn't. (a slight contradiction, mentioned earlier, is that while loading webpages to get to the myspace upload page, there was one or two slight pauses in iTunes playback -- myspace collecting information?)

I have iTunes 'looked for shared music' and 'look for connected speakers' things unchecked. Would you know of any other tests I could run that could help in a diagnosis (based on the above new information)?

Thanks again for you time.

I don't have much else to suggest.
But since it seems to be something related to file access, perhaps judicious use of the command 'fs_usage' (in a Terminal window) will give a clue.
It will show all filesystem activity (read & write) and indicate which program is responsible.

To look at all filesystem activity, run the following command:

sudo fs_usage

Since this will generate a lot of output, you might want to redirect the output into a file that you can look at later:

sudo fs_usage > ~/my_output_file.txt

You could restrict the output to iTunes' file accesses with:

sudo fs_usage | grep -i iTunes

See this Unix FAQ for basic info on Terminal.

I had a similar problem quite awhile back and had to have my logic board replaced.

The determination that it was a logic board issue came from the hardware test they do at Apple stores, but did not appear through the OSX or Macromedia hardware tests. Lucky for me, I was on the ACPP or I would have been screwed. I can't remember the particulars of the situation, but I'll check back on this thread soon, and if it is not resolved, I can probably retrieve the case notes from the case.
P.S. This is my first ever post on this forum. I'm a native of the MacCast forums.

hi guys.

I ran each of the three terminal commands, and for each getting:

bkprG4:~ Bart$ sudo fs_usage > ~/my_output_file.txt
fs_usage: the trace facility is currently in use...
fs_usage, sc_usage, and latency use this feature.

Hopefully this means something to you :)

You would get that message if you tried to run more than one 'fs_usage' command at the same time. I.e. you can only run one instance of 'fs_usage' on the machine at a time.

If you got this when you first tried to run 'fs_usage', that is rather strange - it would seem to indicate that some other program is running 'fs_usage' behind the scenes.
If that is the case, look in Activity Monitor (set it to show All Processes and in Hierarchy mode) to see what is running 'fs_usage'.

Hi Hayne.

I'll try it again when I get home from work tonight. Thanks for your patience.

Hi Hayne. Apologies for the delay.. been one hell of a week!

Ok. I've rerun sudo fs_usage | grep -i iTunes tonight.
I ran the command, waited 2 or 3 seconds then started uploading a file via myspace.com, via Safari. The upload lasted maybe 40/50 seconds and once ended, I let the terminal command run for another 4 or 5 seconds before I cut/copied the results.

There was quite a bunch of info, so I've saved it as plain text and uploaded it here

Hopefully you'll be able to see the problem. In the meantime, I may have a few spare hours tomorrow morning, so I'll try and get my old wireless setup going again to rule out the new modem/router.

Cheers :)

Most of the output seems to be lines indicating that "Microsoft En" (presumably Microsoft Entourage) is accessing iTunes-related files.
I have no idea why Entourage would be doing this - it seems very strange.
But since there are a relatively small number of accesses spread over several seconds, I don't see how this could be the cause of the observed jerkiness. But it might be something to look into.

I should have recommended that you use the "-w" option when running the 'fs_usage' command - that might give more information.

sudo fs_usage -w | grep -i iTunes

It might also be useful to see which processes are accessing the files that you are uploading and those you are playing in iTunes.
You could see this by keeping the full output from 'sudo fs_usage -w' and then post-processing it later (or just looking at it in a text editor).

sudo fs_usage -w > ~/my_output.txt

alright. I've done a bunch of staff since we last spoke to try and isolate the problem:

1. Got my old wireless setup up and running. Made no difference, i.e.: the problem was there.

2. Connected my Desktop computer directly to the current modem via Ethernet, and there is NO issue any more (<-- I'm guessing that's significant)

3. back to the wireless setup. Quit Entourage and ran sudo fs_usage -w | grep -i iTunes
Not much activity at all in the result, but the problem still persisted. You can see the result here

4. Quit all apps other than Safari, Terminal and iTunes. Ran sudo fs_usage -w > ~/my_output.txt
Got a giant txt file (5mb) vast majority had 'safari' at the end of the lines, hardly any itunes entries.

5. Quit safari, and ran the same terminal command, this time having the Desktop's startup drive (bkprG4) mounted onto my ibook. didn't copy any files over but just browsed through bkprG4's files (which has a worse affect on iTunes than uploading via Safari). This resulting text file is here.

Unless there is something in this file, I don't know what to do, and I don't want to keep hassling you. It may be worth noting:

6. Ran sudo fs_usage -w > ~/my_output.txt without quitting all other apps. In the resulting txt file, there was an entry every second with 'autosync', which is part of my SynchronizeX! Pro backup system. After unning this, I quit this, and all other running apps (see point 4), and still got jerky iTunes performance. This is why it's not noted above.

7. Clean installed Tiger onto the iBook (10.4.6) and tried to recreate the issue. Uploading worked fine on my iBook: iTunes played without issue. Could this mean it's a hardware issue? Or, more specifically, a combination of my hardware, which hasn't changed in a loooooong time, and OS 10.4.6, which I installed for the first time after I had reformatted my whole machine?

Phew...

It would seem to show that the issue might have something to do with the wireless networking on your desktop machine. Or maybe just to do with having that machine on a network where file sharing is going on?

I note two things from that output:
- lots of AppleFileServer activity
- lots of reads from syslogd
The AppleFileServer would be due to the file sharing - maybe that is what is taking the CPU and causing the jerkiness (die to some incompatibility or bug or something)?
I'm not at all sure what would be causing the syslogd (daemon that handles log messages from the system) to be doing all those reads. But it points out that you should check the system logs (using /Applications/Utilities/Console.app)

Does your desktop machine have any 3rd-party hardware? If so, the drivers for it might not be compatible with 10.4.6 (might need an updated version of the drivers).

Do you need to keep the G4 on WLAN ?
It would be a getting-around-the-difficulties way of solving the problem, but unless running the cable is really very complicated, it could be a solution to be considered.

Hi there.

Sorry Hayne, I didn't see that this thread had gone over two pages... :S

3rd party hardware...
Nothing that I could imagine would interfere... HP Printer, Agfa scanner, Billion Bluetooth dongle (don't think that had a driver) That's about it... I'll make sure everything is up to dat and report.

Voldenuit.
It was a feat of Cat5 and power supply cable stretching to get my Mac going directly into the Modem. Unfortuantely, I can't run it directly.

You should disconnect all non-Apple peripherals (like the above) while troubleshooting. Some printers have atrocious software that has been reported to interfere with OS X in several different circumstances.

Hi did you ever sort it?... I get this coming up when Chronosync is running... I think. If you know what it is let me know too. thanks