Fixing the slow iPhone synchronization with iTunes

Updated 28 April 2010 – Looks like synchronizing photos is trickier than I thought! Read the full post to find out why and how to fix it.

Have you ever waited for more than 10 hours trying to just sync your iPhone with iTunes? Well, you’re not alone. I recently just had that exact problem. I started syncing my iPhone at 8pm last night and when I woke up at 7am this morning, it was still synchronizing. And to makes things worse, iTunes don’t exactly tell you what the heck it’s doing at all, not even in the logs.

But allow me to give a little background why my problem happened. It seems that there are many reasons why syncing the iPhone can get so slow. Mine was actually because I decided to create a virtual machine to ultimately host iTunes and be my ‘portable’ synchronization station. But essentially, it’s just like moving your iTunes library to another PC and using it as your new synchronizing point.

So, if your facing the slowness based on the same circumstances as I had, then here’s a solution to your problem.

And to make things a little clear, I had 10GB of music, 5GB of videos, 3GB of photos and another 3GB of Apps on my 32GB iPhone 3GS.. So after waiting for so long for iTunes to firstly backup my iPhone, then proceed to synchronizing it, I finally figured that perhaps it could be due to the sheer amount of data that’s already on my iPhone.

Since I’ve copied over the whole iTunes library over to the new ‘machine’ and used the hold-Shift+open-iTunes step to load my existing iTunes library, I had my music and video libraries all intact. This alone is a real good reason to let iTunes handle all the files when you import it in. I’ve also backed-up all the photos and restored them on the new machine the way it was.

Thus, there’s no real reason why I could not wipe out all the music files, videos and photos off my iPhone and re-sync them it fresh.

And that’s what I did. I just unchecked the options to sync Music, Movies, TV Shows, Podcasts, iTunes U, and Photos. Sync my iPhone so that all those are removed from my iPhone leaving it void of any media files. Once that’s done, I simply just re-enable all those items to be synced again. And voila, I was able to copy all my music files within the hour!

Perhaps you too can give this a try if you find synchronization is taking far too long, it’s just insanely ridiculous.

Solving the slow Photo synchronization

It seems that by simply removing all the photos from your iPhone and re-syncing it won’t solve the ultra-slow synchronization. It could actually be the culprit in the first place! It turns out that it was the actual root cause in my case.

Somehow, if the folder that your are synchronizing from contains a relatively large amount of photos (say in the thousands, mine had about 5000 photos), iTunes would take forever trying to synchronizing it over.

The problem is, iTunes goes through all those photos and builds a photo cache of some sort. I’m not sure what it does here actually but it does seem to be reading all the files within the folder, even if you’ve selectively chosen which folder to synchronize.

If you look into the directory, you’d see exactly what I mean (see the screenshot at the left).

So, in order to resolve this, the quickest and easiest way was to do the following.

1. Disable photo synchronization on iTunes.
2. Move out all photos (and folders) from the folder picked for synchronization.
3. Sync the iPhone to clear out all the previously synchronized.
4. Move over the photos back into  the folder bit by bit (batches of a 200-500 photos seems OK).
5. Sync the iPhone.
6. Repeat steps 4 and 5 till all your photos are synchronized.

With that, you should get your iPhone synchronization all back to normal.