iOS Audio Latency

I tested the real world audio latency of some audio interfaces yesterday with a couple of versions of iOS and found something interesting.

Iodock 48khz 64samples

iOS9 (iphone 4s) 7.5ms

iOS10 (ipad 4) 8.5ms

iOS12 (iphone 5s) 9.5ms

iOS13/14 (iphone 8+) 9.5ms

I tried this with my Focusrite and Peavey HD Link and found the results to be similar. The interfaces under iOS9 reported 3-4ms quicker compared to iOS12-14.

This may seem like a small amount but 3-4ms is a huge difference when performing live.

To put it comparison, I have to use my Focusrite interface at 96khz 64samples with my iPhone 8+ (iOS14) to match the latency value of the iPhone 4s (iOS9) running at 48khzs 64samples. Of course the little iphone4s is not able to do much at that lower setting while the iphone8+ can handle the extra demand given by the higher setting, but in a perfect world to have the same latency as iOS9 at the lower setting would allow the iPhone8+ to do a whole lot more before reaching it's limit.