How to speed up your iPhone 3G running iOS4

Many users with an iPhone 3G have found their phone almost unusably slow after upgrading to the latest iOS 4. If you’re suffering with a slow phone, here’s something that’s worked for a lot of people: a cold hard reboot. And turn off Spotlight search.
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Simply doing a normal shutdown and restart of the iPhone doesn’t seem to have any real effect, as the iPhone shuts down to a disk image. In other words, a normal restart (pressing and holding the top sleep/wake button until you get the red slider, then sliding it to turn the phone off, and then turning it back on again) just puts you right back to where you were.

In order to force the iOS to rebuild (a step that seems to optimize a variety of things), you have to press and hold the Sleep/Wake button along with the Home button for about ten seconds, which will kill the phone and initiate a reboot.

When it turns back on, it will take a while to boot. My iPhone 4 boots from a cold death in about 30 seconds, but when I did the same to an iPhone 3G, it spent more than four minutes on the Apple logo startup screen before I was returned to the Home screen.

One this happens however, you should notice that things are better optimized and far more usable. Of course, the iPhone 3G hardware is a lot more limited in terms of processing power and available memory, but doing a cold boot after upgrading to iOS 4 at least seems to make it a lot more functionally usable.

Turn off Spotlight Search for a bigger, long term boost

Another tip submitted by readers: turn off Spotlight search indexing. From Settings/ General/ Home Button/ Spotlight search, turn search indexing off for as many items as possible. This reduces the overall workload of the system, so it appears to give an overall performance boost that is significant.
Let me know what you experience in the comments below.

via roughlydrafted

Last edited by  lazy_applelover on 08-05-2010 at 07:33:54 PM.

yes this will help up on 3G, but after several opening apps it back to normal again.
you should done this at least 1 or twice a day.
This is just a temporarily job only it won't really solved the problems.
=(

disable multitasking and background image also give a lot of boost on 3g. u can use a tool from cydia ztoggle to disable these function. however iso4 not speedy like 3.1.2.

yeah, I can not stand the speed and go back to 3.1.3 meanwhile this is not the terminal solution, but it did help some, I will  try to find some other useful method, and guys if you find some useful advice, you can leave here just qadeer did, that will great

Last edited by  lazy_applelover on 08-08-2010 at 07:42:34 PM.

Helped with my 3GS