Any ways to further reduce FPS drops and stutters when using DH and C2ME?
When using C2ME with or without DH, chunk generation inside vanilla render distance is significantly accelerated, but using both mods causes massive FPS drops and stutters while generating chunks. This is less noticable with fewer mods, but gets worse with each additional mod (for example FPS drops to 10fps with ~150 mods while walking - not sprinting and 5fps during initial generation on view distance 12).
For the sake of this post I have tested the generation time and fps during generation in various configurations. I am testing this on these high settings to really stress the limits so once I add more mods and use a more reasonable view distance those issues hopefully don't exist at all.
DH 2.3.0-b
C2ME 0.3.0+alpha.0.60
Java Args (these slightly reduced the issues):
-XX:+UseZGC -XX:+ZGenerational -XX:+AlwaysPreTouch -XX:+UseStringDeduplication
View Distance: 32
Simulation Distance: 32
LOD Distance: 256
Quality Preset: Whatever is default because DH keeps changing it to custom despite no changes
CPU Load: Balanced
Bliss Shaders (github) without changes
Not looking around during initial generation only flying up to y150
Setting the CPU Load to Minimal completely removes the FPS drops during initial generation (while not moving) but still causes light stutters and FPS Drops to 40 (instead of 15-20) while moving
Results:
No DH & no C2ME: 2:11m - 130-110fps (gradual decrease with visible chunks)
C2ME only: 0:53m - 130-110fps (gradual decrease with visible chunks)
DH only: 2:43m - 130-110fps (gradual decrease with visible chunks)
DH & C2ME: 1:07m - 20-110fps (20fps during generation with jump to 110fps when no vanilla chunks are being generated)
With DH and C2ME CPU is pinned to 100% during initial generation and while moving no matter what CPU Load is set in DH
AMD Ryzen 5 7600X
32GB 6000MHz RAM (8GB allocated to MC)
RTX 2070
Windows and MC running off a NVME
Modlist (65 excluding libraries): https://pastebin.com/gSx033JxPastebin
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13 Replies
I have also tested this on a seperate instance with only Sodium, Iris, DH and C2ME and there the FPS drops only to about 70fps, but as I said this gets worse with each mod added, especially world generation mods.
I think the best thing you can do is pregen a large area with the generation mode set to INTERNAL_SERVER, so that both normal chunks and LODs are pregenned. That way you don't have to worry about generation stutters again
I plan on making this a public modpack and I cant really expect everyone to pregen their worlds :hmm:
Fair enough. Can you try setting your render distance to a reasonable value? Like 12?
40fps during initial generation. No drops while moving.
CPU Load set to minimal impact
However my previous attempt at making this modpack I just chucked in all the mods I want and only removed the crashing ones and there I got massive stutters and drops to ~10fps even on view distance 12.
This time around I'm meticulously testing every single mod, so I don't have as many installed yet
Anyway I guess if the issues come back when I'm reaching final mod count, I'll probably just remove C2ME if there is no further ways to fix this
Switching back to Balanced CPU Load results in massive lagspikes (but decent average fps) even on view distance 12
Try decrease the amount of C2ME threads
I have no idea, but I’m sure changing the thread count is possible
Solution
Global executor parallelism
You could also change the thread pool priority to be lower than the render thread or internal server thread
I’d also recommend decreasing sim distance dramatically since there’s no reason to simulate that far out
Like to 10, 16 at most
Lowering from default (6) to 4 already significantly improved performance.
From 20fps during initial generation to 50-60fps and 30-60fps while flying, but way less stutters.
And I was using 32 sim distance to test the tick performance mods
Ah
Makes sense
I would personally recommend trying to lower the thread worker priority before manually setting a thread count since that would make better use of each system’s hardware if they had a significantly better or worse CPU.
Do you have ThreadTweak installed?
No I don't, I haven't gotten around to trying fabric mods through Connector yet
Lowering Thread Priority from default (4) to 2 gives a minor improvement.
Further lowering to 1 doesnt seem to give an improvement at all compared to 2.
However combining lower thread priority with setting DH CPU Load to Minimal Impact seems to result in mostly stable 70fps even at 32 view distance
Btw I have also opened a feature request on C2ME github to automatically reduce the CPU resources C2ME takes when DH is present, maybe they'll implement it :MeowNod:
I'll check this as answer found since this seems to be mostly caused by C2ME