mojira.dev
MC-8824

FPS Drop due to Smooth Lighting

In the recent snapshot (13w05a) I am experiencing a great FPS drop compared to previous versions. I am getting ~50-80 FPS (on average) compared to 90-110+ FPS in last week's snapshot.

How to reproduce:
1. Get snapshot 13w04a, and test FPS
2. Get snapshot 13w05a+, and test FPS
3. Have a slower frame rate on 13w05a+

Linked issues

MC-8985 Less chunk updates, less FPS, More chunk updates, More Lag. Resolved MC-8999 13w05b Smooth lighting LAGGGGGGGGGG Resolved MC-9010 Lag Resolved MC-9077 Minecraft FPS drop Resolved MC-9118 heavy frames per second difference from 12w04a to 12w05b Resolved

Attachments

Comments 182

Duplicate of MC-2176.

I don't know if this should be resolved as duplicate. There's a noticeable drop in performance from last week's snapshot to this one, which might be related to changes in the lighting engine.

The difference in fps when switching smooth lighting on and off is also way bigger than in 13w04a.

Alex Polishchuk

I'm pretty sure this isn't a duplicate (though it is similar to MC-2176), because my FPS was never this low, ONLY on 13w05a. Likely just a one snapshot bug.

Can confirm that 13w05a has very bad FPS performance hits. On 13w04a, on a flat-world, I had roughly around 100-125fps, now in this snapshot, I have 30-50fps. This is most likely due to the new lighting fix for stairs. (I assume so anyway.)

Yeah. I really hope the mods will reopen this bug. It is obviously a new issue related to smooth lighting in this snapshot.

172 more comments

Still happens sometimes in the overworld, might be related to light glitches.

@ Jeb: Since you care and try to deal with performance issues (as stated by Grum in MC-11875), please consider doing something about MC-8824 which is not completely fixed as a few already stated. 1.5 did not only introduce a high fps drop issue but a "stuttering" too which did not occur in previous official releases. Like the fps drop issue, the "stuttering" occurs during chunk updates (the more chunk updates, the worse the "stuttering"). 1.5.1 only fixed the low fps issue.

I can attest to the stuttering as it still exists. This issue is exemplified with redstone clocks.

Thanks AHelper. I didn't expect to have any support on this. A lot of people nowadays have high end PCs and they don't encounter stuttering. I'm sure Mojang uses i7s so they probably can't notice it either because it won't occur. I get the impression that preserving decent performance on mid range PCs is not a priority.

Any condition that causes a big increase in the indication "chunks updates" in the debug screen, makes the stuttering to occur. World loading, big amount of blocks destroyed, big amount of entities, big amount of grass being eaten by sheep, any situation that causes big fps drop or the use of "Performance: Power saver" setting in combination with any of the previous even at smaller amounts of chunk updates / cpu stress and redstone clocks as already stated.

Robert Pendell

I actually saw it pretty bad in 1.5.1. Even on my i7 3820QM w/32G ram and a 7970m I would get ~15fps when using a x128 texture pack although that may of been a different report. However on the default texture pack it was closer to the 100 area. Performance seems much more improved in 1.5.2 now with x128 texture packs giving ~130fps in many areas without mods. 1.5.1 needed the optifine mod to be playable.

Alex Polishchuk

(Unassigned)

Community Consensus

FPS, drop

Snapshot 13w05a, Snapshot 13w05b, Snapshot 13w06a, Snapshot 13w07a, Snapshot 13w09a, Snapshot 13w09b, Snapshot 13w09c, Snapshot 13w10b, Minecraft 1.5, Snapshot 13w11a

Minecraft 1.5.1

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