Lurker here, also frustrated with +100% cpu usage from innocuously launching the game with no further interaction, sharing my findings of in-game configuration that resulted in dropping in-play cpu usage down to around 20%, in the hope it helps someone:
Dropping the max frame rate afforded the most noticeable benefit, and allocating more than 1GB memory seemed pointless as it anecdotally used no more than 500MB in play.
spotts2870
Lurker here, also frustrated with +100% cpu usage from innocuously launching the game with no further interaction, sharing my findings of in-game configuration that resulted in dropping in-play cpu usage down to around 20%, in the hope it helps someone:
MacBook12,1 - 8 GB 2.7 GHz Dual-Core Intel Core i5 running macOS Catalina 10.15.4
Minecraft 1.15.2, Oracle Java Version 8 Update 241, -Xmx1G.
Graphics: Fast; Smooth Lighting: OFF; VSync: ON; Brightness: Moody; Fullscreen: ON; Mipmap Levels: 4; Render Distance: 12 chunks; Max Framerate: 30fps; View Bobbing: OFF; Clouds: OFF; Particles: Minimal; Entity Shadows: OFF.
Dropping the max frame rate afforded the most noticeable benefit, and allocating more than 1GB memory seemed pointless as it anecdotally used no more than 500MB in play.