I have been having an ongoing issue where my client runs out of memory, see this thread : Done - can anything be done to fix the block lag? | MineYourMind Community Then i see this today : Horizons : 1.6.4 Bug Reports {PUBLIC BETA} | Page 20 | Feed the Beast Basically says get rid of magmatic centrifuges from your area. Removed them and my memory is stable at 5 gigs for the whole nite. Looks as if I will place it, use, and pick it back up as needed. If anyone else is having memory problems/crashes alot this may be your problem