I don't know if this has anything to do with the slow syncs, I just upgraded to the latest from a semi stable itunes 10.7 and ios 6.1.4 to feel the disappointment shared in this thread (I didn't possibly imagine a year ago when I got a new phone that apple would put out buggier and buggier software with each successive release.. to the point where it is barely usable. This ain't the itunes 10.6/ios 5 combo I remember)
I don't have enough room on the phone for everything so I have about a dozen playlists I sync that are forever adding and removing songs (the settings are "only sync selected songs/playlists"... not one song is synced, but rather a few static playlists for stuff I want to keep on the phone and several smart playlists to make up the difference and swap in/and out songs I can live without but it puts on in a sort of "radio playlist" sort of way). It has to re-evaluate all candidate songs to sync on a playlist each time I sync, so it pretty much means I don't have the problem of songs not showing up when they should (at least I haven't seen that yet)
It takes my computer 10 minutes to sync my phone with itunes over USB (even if I just finished another sync and it has nothing new to sync). I also went into the settings very early and turned off all settings I could find that could be related to showing, accessing or downloading icloud copies (no icloud storage of music for me)
Using open source tools I looked at the iphone's drive contents and I noticed this version of ios (7.0.4) creates a lot of artwork files for the music on the phone (or maybe it always has and I didn't see them all.). In previous versions, and even on itunes, it seems that when you fetch album artwork it saves a single copy of the artwork for the entire album. This doesn't appear to be the case any more. It seems every track gets a duplicate copy of the artwork.
I have a bad feeling ios 7.0.4 (and possibly earlier revisions of ios 7) is spending a lot of its time going through the music and comparing the extracted artwork for each song against the artwork in the files themselves.
This could be an attempt to "fix" the problem earlier ios versions had with artwork that would spontaneously mess up its artwork. (happened to me many times and the only cure would be to remove the offending album from the device and putting it back on)
If anybody has a spare setup to experiment, I would be curious if:
- 10,000 songs with NO artwork, NO metatags would take so long to sync (normal size/duration... average 4 minute songs)
- 10,000 songs of 15 seconds each with NO artwork, NO metatags would sync faster than the above test
- 10,000 songs with metatags, but NO artwork would sync faster/slower than the above
- 10,000 songs of 15 seconds each with artwork AND metatags would sync faster/slower than the above
- 10,000 songs of normal size/duration with artwork AND metatags would sync faster/slower than the above
- songs with varying size artwork (100x100 used for all, then slowly increase artwork size to 600x600, 100 at a time) has an impact.
I am sure some of the problems are related to upgrading the ios from an earlier version and the database is slightly different and other problems are symptoms of a stray gamma ray burst or too many strangers walking a certain way at the same time. I ran into this problem right after upgrading and thought this can't be right... It took me three complete factory wipe/reinstalls before I just let it be and discovered it's not permanently stuck in some race condition, it just takes that long. At least for me, I know that the ios music database has been rebuilt from scratch.
I miss the ios 5 days for the music player and sync speeds.