[MC-186075] GPU usage in latest snapshot significantly higher than before, causing lag or crash for some users

Workaround

There is a resource pack by JellySquid and [Mojang] Gegy attached to this ticket which may mitigate the performance issues introduced in 20w22a by applying some changes to the built-in shaders that Minecraft uses.

You can install it just like any other resource pack. Here's a tutorial if you don't know how to do that: https://minecraft.gamepedia.com/Tutorials/Loading_a_resource_pack

This is the latest version of the resource pack: MC-186075 Shader Patch r4.zip

There are no guarantees from the mod team or Mojang that it works, but many people in the comments of this ticket have confirmed that it improves the game's performance significantly in this snapshot.

Please note that since the rendering changes are experimental and may be changed or removed altogether in future snapshots, the resource pack patch may stop working in in the future.

If you're interested in the source code, here's the GitHub repo for the resource pack.

In the latest Snapshot, 20w22a, GPU usage has significantly increased, causing many users to experience decreased performance, with some being unable to even start the game.

Analysis by JellySquid

It looks like the culprit of this massive increase in GPU usage comes down to the new framebuffer blending technique used to resolve some translucency issues between render layers (i.e. items behind fluids).