Hi, there seems to be a heavy UPS hit when a somewhat large base on Cerys entirely freezes over, noticed on multiplayer. Our base did include a somewhat large belt loop (though i cant say if it was 400 or 1000 belts as we've already removed the mod) for generating plutonium. The only mods used was the 'Enable Planet Mods Lite' mod pack. https://mods.factorio.com/mod/kry-planet-mods-lite

This UPS cost is likely that players were looking at the surface, which turns the solar wind simulation back on.

The UPS hit was bigger while Cerys was being looked at, but it was definitely present while both players were actively working on other unrelated surfaces.

I'll take a look, thanks for the report.

Hi!
I'm also having performance issue. I have a small starter base, and it takes 0.3/0.04/9.4.
I've removed all the accumulators, tried to freez/unfreez, tried every option, but it's still the same.
Here is a link to my save file. Can you check what the issue is?
I have a slightly older version - base game 2.0.66, Cerys - 4.10.1
https://www.dropbox.com/scl/fi/zjlofqrt8j94nma5kcdor/cerys.zip?rlkey=4gndt09xxy38asg2bmdsgnplk&st=beax7fsr&dl=0

Hi there. Cerys has some baseline performance cost, even when nobody is on or looking at the surface and the base is small.

After the minor improvements in 4.12.4, the time usage in this case is proportioned approximately as follows:

• Radiative towers: 10%
• Custom ice melting: 0% (this does not occur when players are not on or looking at the surface)
• Solar wind: 50%
• Dynamic lighting: 40%

Although the latter two effects are heavily optimized when nobody is on or looking at Cerys, they still incur some performance cost as the mechanics are not native to the Factorio engine, yet need to be partially simulated for the behavior of plutonium and solar panels.

Hi!
Thanks for your explanation!
I updated to version 4.12.4, but had to re-enable Janus as I have it installed.
I tried to uncheck "Dynamic lightning" and check "Freeze solar wind", as I'm not planning to use mixed-oxide reactors for now. Radiative towers are completely dead. Base is completely frozen. This allowed me to squeeze out some ups, now Cerys takes 0.15/0.05/5. But according to your explanation it should be like all zeroes. I don't get it.

Those percentages are very approximate based on looking at your original save and settings. There is also lots of control flow logic which becomes higher in proportion with those settings turned off. If you add heat pipes, cooling those also takes some UPS (though less-so in 4.12.9 due to heat pipes now cooling in batches).