Slow rendering chunks, Holes in the world, slow tnt redstone mobs dimension loading, rendering blocks , entities,
redstone Problems: Pistons slow not rendering
repeaters dust and torches 1 tick equals 10 sec
(redstone computers don't even work)
Constent crashes
not out of memory but keeps saying false warnings
changing FPS of other settings doen't help
no other programs are running
skin not loading
Still finding more bugs
Comments

Please put only one bug report in each ticket. It is very difficult to keep track of bugs when they are not in their own tickets, and it is easier for you to make multiple tickets than for the mods to separate them.
And please use the search function in the future as all of the issues are reported multiple times.