How much RAM is there in an an iOS (Iphone/iPad/iPod Touch) Device?
Currently released Apple iOS devices have the following amounts of working memory:
iPhone = 128 MB
iPhone 3G = 128 MB
iPhone 3GS = 256 MB
iPhone 4 = 512 MB
iPhone 4S = 512 MB
iPhone 5 = 1024 MB
iPhone 5S = 1024 MB
iPod Touch 1G = 128 MB
iPod Touch 2G = 128 MB
iPod Touch 3G = 256 MB
iPod Touch 4G = 256 MB
iPod Touch 5G = 512 MB
iPad = 256 MB
iPad 2 = 512 MB
iPad (3) = 1024 MB
iPad (4) = 1024 MB
iPad Air = 1024 MB
iPad mini (1G) = 512 MB
iPad mini (2G) = 1024 MB
iPhone and iPod touch has 128 megs of ram, but 3rd party applications should only count on having about 20 megs available.
iPhone
- iPhone (June 2007): 128MB
- iPhone 3G (July 2008): 128MB
- iPhone 3GS (June 2009): 256MB
- iPhone 4 (June 2010): 512MB
- iPhone 4S (October 2011): 512MB
- iPhone 5 (September 2012): 1GB
- iPhone 5S (September 2013): 1GB
- iPhone 6 (September 2014): 1GB
- iPhone 6 Plus (September 2014): 1GB
- iPhone 6S (September 2015): 2GB
- iPhone 6S Plus (September 2015): 2GB
- iPhone 7 (September 2016): 2GB
- iPhone 7 Plus (September 2016): 3GB
iPod touch
- 1st generation (September 2007): 128MB
- 2nd generation (September 2008): 128MB
- 3rd generation (September 2009): 256MB
- 4th generation (September 2010): 256MB
- 5th generation (October 2012): 512MB
- 6th generation (July 2015): 1GB
iPad
- 1st generation (April 2010): 256MB
- iPad 2 (2011): 512MB
- 3rd generation (March 2012): 1GB
- 4th generation (November 2012): 1GB
- iPad Air (November 2013): 1GB
- iPad Air 2 (October 2014): 2GB
- iPad Pro 12.9" (November 2015): 4GB
- iPad Pro 9.7" (April 2016): 2GB
iPad mini
- 1st generation (November 2012): 512MB
- iPad mini 2 (November 2013): 1GB
- iPad mini 3 (October 2014): 1GB
- iPad mini 4 (September 2015): 2GB
Apple Watch
- 1st generation (April 2015): 512MB
Apple TV
- 2nd generation (2010): 256MB
- 3rd generation (2012): 512MB
- 4th generation (2015): 2GB
iOS doesn't use swap space, therefore, only RAM will be available to processes. (That said, iOS does support paging executables.)
As Mehrdad Afshari says, it's 128Mb (except for the 3GS which has twice that), but why do you need to know? Not all of it is accessible to programs and the exact amount varies. Presumably activities like running iPod in the background saps some memory and OS2.1, for instance, seemed to leave less free memory than 2.0.
The key, application wise, is to cache stuff rather than require everything in memory and to heed the memory warning notifications. Your app will be forced to quit if you don't. (If it quits with status 101, you were using too much memory.)