iOS available architecture issue

Question

I'm little bit confused about the architectures available in iOS build settings.

I found that there are 4 types:

1. i386
2. armv6
3. armv7
4. armv7s.

I know i386 is for simulator, armv6 is for iOS devices (older devices, think so).

But I'm confused about armv7 and armv7s.

1) What is the difference between armv7 and armv7s ?

2) Will the armv7 and armv7s architecture based apps support older iOS version ?

I searched but couldn't get any useful information.
Please help me to understand the difference, thanks in advance.

Answer 1

The i386, ARMv6, ARMv7 and ARMV7S are processor architectures (instruction sets), the ARMv7S is found in the iPad 4 and iPhone 5 (with the Apple A6 processor).

The Apple designed processor A6 is the first one to be of the ARMv7S architecture. It's fully ARMv7 compatible, but has some specific optimalisation added by Apple. These optimalisation will not work in normal ARMv7 that is why they added the s.

Wikipedia calls it Switft and AnandTech has a nice post about:The iPhone 5 review - Decoding Swift