Affects Version/s: Minecraft 18w43b
Fix Version/s: None
Environment:*Java version:* Java 8 Update 151 (32- and 64-bit)
*Processor:* Intel Core i7-7700K CPU at 4.20 GHz
*Video card:* Radeon RX 480
*RAM:* 16 GB
*OS:* Windows 10, version 1803
*Minecraft version:* 18w43b
Upon loading up an extant world or creating a new one, the game mostly runs at 55-60 fps, but will intermittently and completely stop for 0.25 to 1.5 seconds. This does not seem to happen if the player stands still.
With the debug screen open, a single spike visibly causes the frame rate to drop to 27, 14, or even 0.
Pressing Shift + F3 to open the debug menu with graphs sometimes causes the game to crash with an unknown error.
EDIT 2018-10-24 22:24 - I just managed to get the graphs without a crash. Attached is the FPS graph showing one such spike.