When testing this snapshot on a server. Hosted by Windows 10 Server Machine (With 24GB Ram) I have worst frame rate than 1.13-1.14 with micro stuttering and fps drops each new chunk was loaded. 4GB of ram was loaded on both server and client. Chunks loaded at 8. Getting 40-70 fps
40 when the frame drops and
70 when chunk fully loaded
This happens in every second of the new world chunk or previous chunk is loading, which causes freezing. Now when exploring the nether this was a nightmare. 20-80 fps in range. 20 fps when the fog changes color with different particle affects. As my best when staying still was 80 fps. However this can be changed with rendering chunks at 16 which my thought was its going to be worst. Turns out NO Its actually stays stable with 40 fps in the overworld with no micro stuttering even the nether was playable at 40-50 fps this is mind blowing on how loading more chunks on client make the game stable (WHY? NOT SURE) but players would think loading 8 chunks be fine and better fps/stable which isn't happening in this snapshot.
1.15.2 I run the same Windows 10 Server Machine I get in the overworld around 100-150 fps. Nether 90-120. Clearly this was a performance loss on the new snapshot. 😞
Client System Info is in "Environment"
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Thank you for your report!
We're actually already tracking this issue in MC-164123, so I resolved and linked this ticket as a duplicate.
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This is happening to me too. I normally get 237 FPS when playing the snapshot, when loading chunks, the game slows to a crushing 12 FPS to 3 FPS. Much more than noticeable. It's practically unplayable when it happens, which lasts for about 8 seconds then returns to a playable framerate.
I've noticed this occurs when large groups of mobs in the Nether appear with the new spawn mechanics and reducing the render distance to less than 5 reduces the impact of these framerate drops.