The S3's cpu and memory must be more than capable to handle this.Most of the time, custom kernel have no effect (may be battery). But in the particular case of delta creation, a smart scheduler may have a great impact on the performance!
On my S3 with stock kernel it is super laggy. I found this morning better parameters.
I am wondering what I can do to improve experience.
If you have an idea...
Regards
There must be a lot of read/write activity going on for this.
For your information I'm using the external Samsung 32GB class 10 sd to store the backups.
If you are using a stock ROM and kernel there are probably not much parameters you can tune there except maybe the sd-card read/write cache. I'm using 2048k cache atm.