I have ~250k mirrors and wanted to disable the beams to save performance. However, despite the setting saying it takes at most 60 seconds to update, after waiting for several minutes the beams are still there and performance is also unchanged.

Rebuilding mirrors leads to no beams as expected, but yeah already built entities appear to be unaffected.

Interesting, I believe that comment may be out of date and the beams may take a full day to reset in that case. Will include a fix to this in the next patch, so they immediately change, which I'm still working on in free time.
Out of interest, as my tests never got that big, do you have any numbers about how the setting effected performance/how the mod is performing in general?

The day length is set to 12h days with mods, so that would also explain why it didn't change even after waiting for a while. Thanks for the info and incoming fix.

As for the performance of the mod and performance numbers - it worked pretty well for a long time, only at this current scale with 465 solar towers and 256k mirrors did ups finally dip below 60 (around 50). For reference, playing with Exotic Industries and pretty far into the lategame and concentrated solar is the main power source with now close to 30GW peak. Debug info says 3.7 million entities total with 840k active and 122k chunks. So it's a sizeable base but nothing too big, with a lot of explored map.

Of 19ms total update time, around 8ms was spent on beams, hence expecting that it's the mirrors which are the big performance bottleneck right now. Fluid updates are still below 1ms so that seems to be negligible in comparison.

Can't give a comparison to without beams yet since they're still around even after changing the day cycle length down to vanilla and waiting a few ingame days.

Hardware is 13600K @ 5.2GHz P-Cores, 2800MHz DDR4, ASRock Z790 Pro RS/D4

Thanks for that info, great stuff. Unfortunately, the beams are spawned with the lifetime of the day cycle when they are created, so that 12 hour wait won't be going anywhere :(

Kinda expected that, will let you know once that time has passed how performance is affected.

Looks like the beams are all gone already, and ups are noticeably improved. From about 50ups up to 80 - 90ups, beam update is not even listed any more in performance stats. With that, it's actually still performing pretty reasonably at that scale, if you're not focussing on optimizing for ups too hard. Nice.

Nice to hear, optimisation was a pretty big goal of mine - despite the huge amount of mirrors, the tower update only runs once per tower, with the rest cached (number of mirrors pointing to it), so should be very light, while beam update is more granular.
Used the be a setting to reduce the rate of the beam update from its default, but the settings were quite obscure, I plan to bring that back better in a future update in a more friendly way.
(Reducing rate won't introduce stutters, as only a proportion of beams/towers are handled every tick, 'rate' is the number of ticks to iterate through everything once)