I have had the iOS 4 on my iPhone 3g for almost 24 hours and haven't noticed anything weird or off the wall. I did notice that not much in iOS 4 is available on the 3g. No multitasking for one. I had some problems with Exchange, but a reboot of my phone fixed that.
I also didn't have any problems either. I'm currently using the gm seed, and it seems not much different (speed-wise) on my 3G compared to the previous OS version (I was using 3.1.2 before)
It's worth mentioning that when you do an upgrade, the Spotlight process must go out and re-index all of the content on your phone. This is a background process that might take a few hours to complete, especially if you have a lot of content and email.
Most people are saying that after a few hours the phone is noticeably faster or at least back to normal.
I think what is happening here is this background Spotlight index is killing performance right after the upgrade, and people are mistaking this for terrible long term performance.
I've been using 4.0 on my 3G since the initial betas were released. I was hoping the GM version would address the performance issues, but no luck - I've had it installed on my phone since it was released around WWDC, so I don't think this is a Spotlight issue. Glad the iPhone 4 is coming tomorrow; the 3G really is almost unusable for me at this point (Google Maps especially).
The moment after I upgraded, the phone was completely useless. I restarted twice and it picked up a little speed. Its now 24hours later and its still extremely slow and laggy.
I've always found that for some reason with OSX (which is perhaps somewhat comparable), I get the best results with a fresh install. I think Apple sometimes doesn't do the best housekeeping.
My 3G (w/ the 4 GM) routinely freezes to the point where it just stops responding to input. I'll probably attempt to downgrade it to 3 soon. Which, I honestly don't mind. I mean, I would rather Apple not even support the 3G with iOS 4 rather than have to deal with this user experience. It's not like it can even deal with background tasks anyway...
Same problem here; iPod frequently doesn't respond to headphone controls, and apps slow to a crawl and become unusable ( >1 minute to respond to clicks).
Do you test/debug apps on your phone? Is it possible that this is triggered by using debugging tools? It seems like everyone else is not seeing what we're seeing.
Interesting, my 3G had the exact same problems as you (just froze and didn't respond to anything for like minutes at a time) with OS 3. But the problems have gotten a lot less frequent with OS 4 for me.
I read somewhere that upgrading a 3G from OS 2.x to one of the OS 3.0 betas and then to OS 3.0 final, without doing a full reset somewhere in between would cause this problem. OS 3.0 was sluggish as hell for me until OS 4.0 beta came out and I did a full reset. I'd get random pauses and freezes just like others here are reporting. After the full reset, the 3G was running smoothly again. I just upgraded to 4.0 final and it is smooth too.
A full reset kind of sucks. We're not talking a restore here. Just start from scratch. With the exception of one or two apps though, my data was in the cloud so it was largely painless to get everything back in sync.
Then why do people pay more money for phones that haven't been upgraded? I figured it was because you can't go backwards and the newest versions can't be unlocked.
When you try to install a firmware on your device (whether it's iOS 4.0 or iPhone OS 2.0), Apple signs the firmware using some combination of a unique identifier and other things to make sure you should be able to install it. When they release a new firmware, they typically stop signing the old firmware days or weeks afterwards, meaning you can't downgrade to it anymore. Also, there are checks on the device so even if you do manage to install it, you'll need to run certain commands to get it to boot up the first time.
The newer 3GS is harder to downgrade and you also can't downgrade the baseband (modem firmware) version, but you should be able to downgrade the actual operating system without any trouble.
Got it working. I followed the instructions and got stuck with error 1015.
I had to do two things.
1. Switch of your iPhone and put it in DFU mode with following instructions
- Click the Home + Power On button for 10 seconds exactly
- Release the power button and continue to click on Home
Performance is indeed bad. I downloaded iBook. It takes about a minute till the first page of Winnie the Pooh is shown. Flipping through the pages is slow.
Anyone noticed any changes regarding signal strength or reception for better or worse with iOS4? When I upgraded to OS3.1 and I went somewhere without coverage, my 3GS sometimes refused to come back from "No Service" until I either did a cold reboot or switched in and out of Airplane Mode. Then it would work fine again, so I suspect it was a software issue and not the network (Vodafone in Perth, Australia).
Has this happened to anyone else here and have you noticed any change in iOS4?
I haven't had any issues yet. I have a 3G and it seems to be running great. I just have to update some apps that have an update in the app store and I should be right.
I think I'll wait for 4.1 in the fall. If they couldn't spare the engineering time to get their 2nd flagship product up to speed with iOS 4 for the iPhone 4 launch, then you can imagine them de-prioritizing the no longer for sale iPhone 3G too.
I think my iPhone 3G goes super fast with iOS4!! Rolando 2 goes Like crazy, its 2x faster (some bug idk), Safari goes faster and Apps load slightly faster! I don't understand how this happens, but it's way better!
I've seen claims in both directions. To play it safe, I'll keep my 3G on 3.x. There was only 1 new feature in iOS 4 (that also worked on 3G models) that attracted me anyway: the unified mailbox view thing.
Actually I have a short list of desired improvements that might make it worth it, despite a speed drop:
* photo synching to my desktop (so not limited to the lame select-up-to-4-then-email-them thing, which is way too time-consuming if you have many photos and/or add new ones frequently)
* in Safari, when hit Add Bookmark, and goes into the Bookmarks view, it should start in the top-level collapsed state, that way I can quickly navigate to the right folder to select. Divide and conquer would speed it up in the case where there are many nested folder categories.
* making the Back button in Safari take you back to a cached, post-rendered view of the previous page -- rather than having to re-fetch/parse/render all over again, wasting my time, battery and the network (groan)
* cached application state restoration in general, consistently -- i realize the critical ingredient here is partly having enough memory and flash, so just beefing up the hardware with each new model refresh should get us to an ideal state eventually. Right now, lots of frustration and wasted effort when I go back in Mail and Safari and it's forgotten where I was last at and has to redo everything, sometimes reseting to some default state (such as scrolled to the extreme top rather than down in the middle where I was)
making the Back button in Safari take you back to a cached, post-rendered view of the previous page
This behavior is extremely frustrating. It is similarly annoying when Safari reloads a page because the previous copy has been reclaimed due to low RAM. Rather than flushing the previous version entirely, it would be much nicer for Safari to write the old version to flash. Reloading from flash would be much faster, and would also prevent the page content from changing on reload (e.g., Google Reader won't reload "read" items on reload).
