Minecraft snapshot 18w47a taking up too much ram

When I try running minecraft snapshot 18w47a, the newest one with new textures when I try running it lags the game to the point of not being able to move, but every few seconds. Usually in any other version, before the new textures I was able to have 60 fps constantly. Even when I try allocating up to 4 or 8 GB to run it it still runs slow, just slightly faster but with the same problems, in any other version it only takes 2 GB allocated data to run it, could it just be i have to run it for a bit?