Iphone 3G slow after update to IOS4

After enduring iOS4 on my iPhone 3G for over 6 months, I finally bit the bullet and downgraded to 3.1.3. I always had faith that apple would deliver a solution and whilst there were some marginal improvements in the subsequent updates to iOS4, my phone still wasn't as fun to use as it used to be. I had tried all the various solutions on this forum, such as reset and restore etc etc. This would lead to a marginal improvement in performance for a week or so before slowing down again. Sometimes I would not even be able to answer a call as the slider would not respond to my touch as the phone was ringing.

Anyway, in light of the fact that it was very doubtful Apple would be releasing any further updates to iOS4 targeted for iPhone 3g, I downgraded to 3.1.3 a couple of days ago following the lifehacker article. It was immediately obvious to me how much faster 3.1.3 is compared to iOS4. It felt like I had an old friend back and left me wondering why I had put up with iOS4 for the last 6 months just so I could have folders and a slightly improved iPod application. Everything, Everything runs much much faster now.

I was lucky that I found an old 3.1.3 backup in my time machine and restored that to my phone. Most of my info on the phone is stored in the cloud so that wasn't a problem. The only thing I was concerned about was my SMS messages and Photos. I backed these up to my Mac before doing anything but eventually I was able to restore my SMS messages and Camera Roll photos after jailbreaking and manually copying a few files from my iOS4 Backup.

All round, I couldn't be happier with how it has turned out, now I don't have to upgrade the hardware anytime soon.

I think I pretty much did the same thing as you. I knew about that LH article a while back but I didn't downgrade, instead I restored a couple of times, got it replaced for free under AppleCare, turned of MMS and Spotlight but those solutions were only temporary and never restored it to a pre 4.0 performance.

My tunes would skip, apps would crash, lock screen would lock-up; all these indicating the obvious fact that iOS4 was never meant for 3G.

I decided to finally downgrade after my AppleCare ceased and now I am a happy camper. I just wished I had retained copies of apps which had lost compatibility with 3.1.3 eg DailyBurn and Keynote Remote.

I won't be upgrading anytime soon either and I am skeptical bout choosing another iPhone in the future.

The link for instructions to downgrade back to 3.1 is:

http://findtut.com/easy-steps-to-downgrade-from-ios-4-to-ios-3-1-3-536547

Looks like x1daydreamer6x maybe on to something....

From The Next Web:

Does iOS 4.1 fix slow iPhone 3G units? Yes.

x1daydreamer6x

I had the same problems.
Last night i downgraded to 3.1.3 again!
This is so much better and faster.

You need to restore your 3G with iTunes (not 9.2, you need an older version) in DFÜ mode.
After that you get an error ( mine was 1015error).
Thats fine. Then you have to reboot your phone with RecBoot.

Thats it...

Following upgrade to os 4 my iPhone 3G 8th was so slow I could hardly use it.

I tried a few things but the cure for me was a forced reboot.

This can be initiated by holding down the home button and power button for 5 to 10 seconds until the apple logo appears.

Now it runs better than before the upgrade.

Well, right after installation of the iOS4 I have noticed that my iPhone 3G slowed down but I tried to make myself believe it is the way it should be. However when I tried to use Safari and iPod at the same time, that was the time when I actually got pain in the back.

Checked the forums and learned it is not just me, but in general iOS4 should have not been allowed for iPhone 3G as well as for the original iPhone, because out of all the perks promised iPhone 3G users get only:
- several new wallpapers
- folders
- slightly twisted mail account viewer
... and that is it, if you are not counting the slowest iPhone 3G ever:-)

So I downgraded my iPhone 3G to 3.1.3 and now it is fast again. It took a couple of hours to surf the Internet to find the right guide, but I did it. For folks who are on the way to get it done, I have put together a simple procedure, so e-mail me to vkutcherenko@gmail.com and I will send it to you.

iPhone 3G user

Message was edited by: VNK001

If you put the iPhone in Airplane Mode (and wait 2 minutes) do response times improve? There is evidence that when an update (instead of a cold install) is done the process "touches" all the Contacts and Calendar entries and, if your IMAP is out of sync, it rebuilds the mail box from the server.

http://discussions.apple.com/message.jspa?messageID=11783786&tstart=0

If your iPhone 3G is doing all this using the new "background processing" feature. it might account for some of the experiences being reported.

Closing Safari tabs does seem to make a big difference for me.

If Safari running in the background is actually the root of the problem, in a twisted way, this is an excellent example supporting Apple's position of very tight restrictions on "multitasking": It only takes one bad citizen in a generic multitasking pool to totally demolish the performance of the whole system. Now they just need to make the built in apps follow the same rules and restrictions as third party apps.

Thanks, AndrewsTech.

My 3G phone was slow after i upgraded to ios4 and even did a factory restore. Then I read a posting on here about doing a hard reset and that made a huge difference for me and a friend of mine who was experiencing the same problem. How to do it - hold down the home key (round key on front) and the top button until the red slider comes up, but keep holding (ignoring the slider) until the phone shuts down on its own and restarts. hope that helps.

I also tried doing this, and it improved a bit.
I have this FreeMemory app, which many of you may know. Well, with the previous system I would usualy get values between 28 and 30 MB of free memory. Now, with iOS 4 I would never go over 3, and most of the time the values would be around or under 2! After I dis what Andrews Tech suggested — closing Safari tabs, disable Spotlight searches and turn off a few more things (alerts, etc), I'm getting values between 6 and 7. Of course, I don't know how accurate or meaningful this values are, but the phone seems a bit more responsive.
Anyway, I never felt, as most of the people in this thread, that iOS4 had made the phone unusable. For me the effects have been 'acceptabel', so much so as I would hesitate about downgrading if I had the chance. Perhaps, it also has to do with the number of apps installed, number of screens, folders, etc. Just guessing.

Well, I'm glad it's working for you. Closing all Safari pages on the two iPhone 3Gs I have doesn't make a discernible difference in speed of other apps I have tried running. Safari still eventually crashes on both phones even when only viewing a single page at a time.

I don't have to reboot my phone every day either, but, the sluggishness and extreme slowness is still there in many apps. A reboot does help to temporarily speed things up for a few hours, so, I've gone back to rebooting the iPhone at least once a day to make the phone usable. But, this version of the OS is a LOT slower and unstable than the previous one was, that's for sure.

I found this thread and followed his easy instructions. Believe it or not my 3G sped up. There are still some apps that bomb, ie. Fox News has to be started twice. My load times have increased. Try it.

http://discussions.apple.com/thread.jspa?messageID=11788075&#11788075

Any speed increase you may see by doing this is only because you restarted your phone and will be temporary. Your 3G will slow down again after using a few apps for awhile. I wish people would stop posting all these different steps as the solution. Turn this off, reset that, re-install this, rinse, repeat. It's a waste of time.

The problem is that the 3G hardware is not powerful enough to run iOS 4.0 as it stands. The only real solution will be an iOS update from Apple that fixes the problems.

TomNYC wrote:

The problem is that the 3G hardware is not powerful enough to run iOS 4.0 as it stands. The only real solution will be an iOS update from Apple that fixes the problems.

Exactly and more specifically, iOS4 uses 95% of the 3G iPhone's RAM doing nothing but being on (and running a small diagnostic program that measures the use of the RAM). The 3G has 128MB of RAM, 11MB of which is reserved for the graphics card. That leaves the phone with 117MB of available RAM. iOS4 uses about 111MB of the 3G's RAM leaving about 6 MB for use by 3G iPhone Apps.

The suggested "Hard Reset Voodoo" is definitely +temporary at best+ and +completely unacceptable+.