Red Stone Block and Command Block make process heavier.

I use a lot of Command Block with Fill Clock. When the sum of Red Stone Blocks and Command Blocks are less than 64 in same chunk, there are no chunk update. But when it reach to 64, it happen outbreaks of chunk update. The number of chunk updates are about multiple of 40.

I'm sorry that there are few informations.
These are screen shot multi play and single play.