I had the same problem and fixed it by doing a full restore and setting up as a new phone rather than restoring from back up.
You'll lose all your data and have to re-sync all your music, apps etc from itunes but you phone will run faster. Make sure to sync with itunes and transfer any purchases made on the phone before doing the restore.
I have the same issue, applications seem to take 2-3x longer to load, and more depressingly, the time is not determinstic so the phone keeps breaking the rythm of using it.
I also have a problem with text input where the character popups lock up, sometimes it will complete the iunput of what I typed, sometimes the application fail terminate (buffer overflow?).
unfortunately theres only 1 solution & apple dont want you to do it (they want you to get another iphone. (hpefully a faulty iphone 4 there selling - now with a feww "bumper" so you dont touch the case & loose the signal!)
I downgraded to 3.1.3 its not too hard to do (cant give you links but do an internet search for "iphone 3g downgrade 3.1.3" or remove iphone OS4...
basically all you need is the correct 3.1.3 firmware (might be in your recycle bin - iOS4 deletes your old one in the hope you dont find it - if not you can download it from a few places, make sure its the one for your model - iphone 3G)
hold left shift (if useing windows PC) when clicking restore & it'll ask you which one you want to use (otherwise itll be the same 4.0.1 or whatever you used last, point it at the 3.1.3 one)
let it restore & you need recboot to finish it (& libUSB too especially if your using vista)
when I did it I lost everything so make sure you back up everything 1st.
but yeah, 3.1.3 works just like you remembered it & all the apps you updated to be 4.0 compatible still work with 3.1.3
& http://www.apple.com/feedback/iphone.html - give them feeback - they wont reply, but if enough are logged maybe they will bother to do something....just dont hold your breath.
I'm with Noiseboy here. RESTORE your iPhone!
I had exactly the same throw-it-out-the-window frustration with my 3G on iOS4. A tech I spoke to (at iPhoneDoctor in Sydney Australia) correctly surmised that I had simply followed the normal upgrade process from iOS3, and said that 3G users who RESTORED had no such issues.
I’ve just done it: it took about an hour for backup, firmware update, auto-download of latest iOS from Apple’s servers, reinstall and then re-sync from backup. All perfectly straightforward - but requires you to be really patient as progress sometimes seems to stall for several minutes (especially when transferring large apps or movies - just hang in there!).
And the result? – BRILLIANT!! I’m now happily running iOS4.01 on a 16GB 3G – and it’s just as snappy as it ever was!!
Spread the word - I have no idea why this fix is not more widely known!
I had a sluggish phone even AFTER using the restore instead of update. A couple apps like MoodAgent or MakeMyMusic wouldn't run at all. I found a really useful solution in the link at the end of this post. In general,
1. Close the old Safari windows when you close the app. The 3G has only 128M of working memory and they keep using it even after you close the app if you don't "x" them out.
2. In the settings tell spotlight to only index those things you really need. I only use it as an app launcher so I turned off all the other stuff which helped a lot.
3. Keep about 10% of your storage free. I'm a glutton and removing 4 of the 10 audiobooks helped a lot in the bookmark.app audiobook player.
Here's the original link for anyone who cares....or needs a little more zip.
Same here. The first 2 days after updating 4.01 everything seemed faster. But than again, during the update all music, photos, textmessages etc were erased with no way of recovering them.
Now after, what is it, 2 weeks,
* the phone needs two minutes to activate the keyboard
* the pick-up key gets stuck
* it takes ages to open picture roll with all 14 pictures in it
* email messages get messed up in the wrong directories
* and I don't even want to talk about the apps that Apple has no control over.
I don't dare to connect to iTunes again as it took me 5 to 6 hours last time to update and correct everything. Deeply disappointed with the quality of 4.01 and the lack of possibilities to get support. All one seems to be able to do is complain and share stories here. Telecom provider takes no responsibility and sys it is Apple, Apple says to go to the reseller. Catch 22 or what?
I second that. After 4.01 it seemed to work somewhat faster, but that was only the first day or two. Now it's just as bad as it was before that update. It's absolutely horrid.
Apple are idiots and they lost my cash short term, if this crap on all their recent products continues, they might just lose me long-term.
Seriously. Try the things I posted about 4 messages back. My 3G went from dogmeat to working as well as it ever has. The real problem is the 3g has half the memory that the GS and 4G has for apps. Safari doesn't shut down when you close it. If you take a second to close the open windows before exiting it frees the memory and things work a whole lot better.