Hello, you have to add more options in the Graphic Options, since that generates Slowness of the FPS when playing Snapshots in the Bad Computers, and even in Flat Worlds, the 1.13 is very Slow in FPS, so they only added 2 Graphic Options, you have to add more Options, such as Reduce and / or increase the Animation Quality of the Blocks, entities, etc, or Deactivate them, other causes of Slowness are the Illuminations, there must be a way to Optimize them, Reduce the Slowness of the Water and Lava, Reduce the Graphics of the Explosions, etc, all these options do not have the Optifine, and you must add them to Minecraft, that would be very useful when playing without Optifine.