"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Apple's New iPhone 5 Has 1GB of RAM
The iPhone 4S and iPhone 4 both contain 512MB of RAM for developers to work with. Running out of RAM can cause some performance issues as existing applications or documents may have to be purged from memory from time to time.
iFans first posted confirmation that the iPhone 5 has 1GB of ram based on the part numbers listed on the A6 chip itself. After some investigation with Kyle Wiens from iFixit, we've been able to confirm their findings as well, using Samsung's own product guides.
The chart above comes from Samsung's 2012 Product Solutions Guide (PDF) which lists part numbers of various memory parts they have for sale. The iPhone 5's A6 part number lines up with the family of 8 Gigabit mobile DRAMs which translates into 1GB of RAM. The A5 part family is also listed and accurately shows 512MB of RAM (4 Gigabit).