During the last patch (1.12.1) I was starting to experience stuttering within my game as more blocks within the world loaded in and as more things were added to it. At first I thought it was a simple issue of the server I was in, but upon further looking into it was a issue on my end. So when version 1.12.2 finally launched I decided to look into it and found that the game was only allocating 243 M of data for the game to run on and it would frequently cap that before resetting only to repeat the process. I tried messing with the JMV arguments, changing what memory is used and setting it to M, but nothing seems to be working. This error makes it incredibly hard to do longer sessions in minecraft and I hope there is a solution out there that I may have missed that could fix this.