What I expected to happen was that when replcing the blocks in a void world it wouldn't cause lag.

What actually happened was it cause lag when replacing blocks in a void world and the faster the the block was replaced the more lag was caused

I was replacing some blocks in a void world by quickly destoying then replacing the blocks and noticed some lag, so I brought up the debug screen and noticed a a slight drop in fps. I then tried to do it as fast as possible finding my fps was cut in half from 60 fps to 30 fps

Steps to Reproduce:
1. Create a New Superflat Void World (New World - More World options - Worldtype:superflat - customise - presets - the void - use preset - done- done - gamemode:creative - create new world)
2. move toward the centre of the platform (close the cobblestone)
3. select any block in your inventory
4. bring up the debug screen by clicking the f3 button
5.destroy and then replace the block quickly
6.noticable amount of lag shown by the fps dropping