Why does iOS 8 needs extra storage to installed

[dare2winn]

i have iphone 4s and its total storage capacity is 13.6 GB approx and as far i think ios 7 also has occupied some space to be installed so why doesnt ios 8 uses that memory while installing ? and i have read lot of rumour that ios 8 makes device slow specially iphone 4s so when i feel i did mistake installing ios 8 then is there any process to downgrade to ios 7 agian? if yes what is the safest process? please help

 

[AppleSarge]

I am not sure why, but I believe my 64gb iphone 6 was at 59gb out of the box

 

[dacreativeguy]

i have iphone 4s and its total storage capacity is 13.6 GB approx and as far i think ios 7 also has occupied some space to be installed so why doesnt ios 8 uses that memory while installing ? and i have read lot of rumour that ios 8 makes device slow specially iphone 4s so when i feel i did mistake installing ios 8 then is there any process to downgrade to ios 7 agian? if yes what is the safest process? please help

Because you always have to have some sort of operating system running. In the old days, you booted your Mac from CD and the OS ran off of that. You need double the space to upgrade your iPhone because you have to copy the iOS8 files to the phone and use iOS7 to install them. Once installed over 7, the iOS8 installer you downloaded is erased.

If you connect the phone to iTunes, just turn off music or video synching to free up space, do the update, and then turn the synching back on. Worked fine for me.

 

[dare2winn]

Because you always have to have some sort of operating system running. In the old days, you booted your Mac from CD and the OS ran off of that. You need double the space to upgrade your iPhone because you have to copy the iOS8 files to the phone and use iOS7 to install them. Once installed over 7, the iOS8 installer you downloaded is erased.

If you connect the phone to iTunes, just turn off music or video synching to free up space, do the update, and then turn the synching back on. Worked fine for me.

thanks for the great info