Slow iPhone 3G after iOS 4

My 3g is working great on iOS 4....Just installing my backup now....Mine was jailbroken on 3.1.2 and now is running great after that....Try just rebooting the phone usually makes things better.

Same thing here. Sometimes it takes over 10 seconds to access a setting on the settings app.

Rebooting has done the trick for most. Mine is running great.

I have sluggishness as well when I installed on my development phone. (Luckily I have another, I just need my apps to run on iOS4).
I've rebooted and all the other things suggested in the thread. It's simply a matter of the hardware inside the 3G vs the newer models.

Do a restore rather than an update. The official release looks the same as the GM release though.

My 3g iPhone is functionally hopeless under OS4.0 in comparison to how it operated under the previous OS.
It is slow in almost every function and I now have video of side by side tests with other 3g phones showing how unresponsive and sluggish a 3g is under OS4. I will be posting these to YouTube.
Apple needs to give us a legitimate way to downgrade our phones back to OS3. If a user has paid $900 to own an iPhone and it still has a couple of years of solid use still in it - then it is totally unacceptable to punish existing iPhone users who have unwittingly upgrade their OS only to find the user experience to be horrid. Offering only the alternative of 'buy a new phone' is not what we need to hear from Apple. We need a way to fix this.

I'm somewhat inclined to agree, but keep in mind that the smartphone market is even more volatile than technology in general. Stuff changes so rapidly and new products come to market so often it is, frankly, unreasonable to expect anything else. I purchased my iPhone 3G 16GB in late October 2008 (it had been out for some time even before that!) so I've gotten a good year and a half out of it. I will probably be upgrading to the new iPhone 4 in the near future and turn my old 3G in to an iPod Touch for one of my kids.

To be honest I didn't find performance THAT bad on the 3G with iOS 4. It definitely bogs down at times, but that is to be expected. Think of it this way...does OS X run as good on a Core Solo chip as it does on a Core 2 Duo? Of course not - it runs, but not nearly as well. To expect Apple to extend the life of your product is unreasonable here -- things change. The fact is the 3G still works fine and is QUITE useable with iOS 4. In fact, I have gotten better battery life and have noticed several tasks and applications are FASTER than they were under 3.1.3. I guess every one has a different definition of speed and usability but I find the claims of the phone being completely unusable to be invalid. You've either had issues with the iOS 4 install which are causing system hiccups AND/OR you have an unreasonable expectation of a brand new OS on 2-year old hardware.

Just my two cents worth. YMMV.

cpavlovec wrote:
I'm somewhat inclined to agree, but keep in mind that the smartphone market is even more volatile than technology in general. Stuff changes so rapidly and new products come to market so often it is, frankly, unreasonable to expect anything else. I purchased my iPhone 3G 16GB in late October 2008 (it had been out for some time even before that!) so I've gotten a good year and a half out of it. I will probably be upgrading to the new iPhone 4 in the near future and turn my old 3G in to an iPod Touch for one of my kids.

To be honest I didn't find performance THAT bad on the 3G with iOS 4. It definitely bogs down at times, but that is to be expected. Think of it this way...does OS X run as good on a Core Solo chip as it does on a Core 2 Duo? Of course not - it runs, but not nearly as well. To expect Apple to extend the life of your product is unreasonable here -- things change. The fact is the 3G still works fine and is QUITE useable with iOS 4. In fact, I have gotten better battery life and have noticed several tasks and applications are FASTER than they were under 3.1.3. I guess every one has a different definition of speed and usability but I find the claims of the phone being completely unusable to be invalid. You've either had issues with the iOS 4 install which are causing system hiccups AND/OR you have an unreasonable expectation of a brand new OS on 2-year old hardware.

Just my two cents worth. YMMV.

Thank you for stating the obvious. I've said this before: It's like installing Vista on a computer that says you can install it, but comes pre-installed with XP. You can't expect (somewhat old) technology to keep up with updates that are clearly for technology being released in the near future. You should start a new thread and post your comment as the first thing for people to see 🙂.

I have the same issue. I restarted the iPhone, I did a hard restart but the problema remains. Hope Apple will do something soon

Despite being hesitant, I upgraded my 3G last night, and I'm very surprised at the performance because it's actually a bit faster than 3.1.3 was. :o I'm wondering though whether a lot of the reported issues with performance on the 3G come from doing an "update" in itunes rather than a "restore". As I understand, and update will simply try and "work around" your existing data on the phone and fit IOS4 in where it can. A restore will format the entire phone, and install IOS4 fresh. I installed IOS4 by choosing the "restore" option in itunes, and of course after this was finished I was left with a completely blank phone. Once that was done (only took about half an hour), I proceeded to hook up to itunes and restore from my backup. I then synched my apps (which took a while, about an hour), and now I'm gradually filling it with music/films again. I'm really pleased with IOS4 so far, the speed of certain things (like the menu transitions, and the browser) has definitely improved on my device. There are the odd moments where the phone will pause for a few seconds, but I had this frequently on 3.1.3 and it's certainly no worse (as I was lead to believe it would be). I'd recommend to anyone having issues to

1. Take a full phone backup

2. Choose "restore" in itunes.

3. Restore from backup afterwards.

Worked great for me.

I have the GM iOS4 installed and have slow issues also. It starts fine but after hours or a day it starts to get slow. Rebooting the phone seems to help until it starts happening again.

Planning on restoring the phone later with the release everyone is getting to see if that makes a difference.

I had same problems and worse. Some apps didn't run at all.

I decided to "downgrade" back to OS3. You can too!

Go to this thread and read about it. http://discussions.apple.com/thread.jspa?threadID=2473976&tstart=0

It needs a restore. When I did the upgrade on my 3G, iTunes actually initiated the backup and restore process on its own. Took more than two hours (the backup and data restore processes were painfully slow) but it did finish. It had to re-do the phone activation and everything, but it was automated and I didn't have to do anything.

Just be sure to wait until everything finishes until you unplug the phone. You will see the "connect to iTunes" graphic and other things along the way. Don't touch the phone during all this.

The phone was very, very slow when the process completed, but I did a hard restart (hold power and home past the red slider) and once I used it for a few mins the speed seems normal.

If your update did not do a backup/restore I'd definitely try that.

Don't forget that Apple were still selling 3G models (8GB version) until very recently.
Do you think those users will be happy that the new software released by Apple on a device that is less than 3 or 4 months old is now very slow?

It is not acceptable that iOS4 is slow on a 3G phone.
If it can't run it as well as iOS3 then they should not have released it, or given a clear warning that the performance would be affected in a negative way.

There are many users who will see the new software in iTunes and upgrade, thinking they will still have a great phone, and they will be disappointed. Things should get better, not worse.