[0.17.25] Pumps not working correctly?

[Kingdud]

So, this may not be a bug, but rather a lack of understanding on my part. Essentially, I have 10 offshore pumps directly pumping into storage tanks, which then have 'pumps' (the 12k/s things that require power) going to a fluid void. I should be getting 720k water/minute, but production stats only shows 648k. A few versions ago (maybe in the 0.17.18 space) I was able to get the full 720k/m. And in 0.16 this configuration would also give me the full 720k/m. Did I miss something?

factorio-bug.png (3.71 MiB) Viewed 1900 times

That's what my setup looks like. I can replace the 'compressor' (the thing with the green dot) with a creative mode fluid void or literally anything else capable of sucking down 12k/s of fluid and get the same result. That isn't the bottleneck.

Also, if I put a pump in between the compressor and the tank, flow drops from 648k/m to ~428k/m. The fundamental problem appears to be something to do with fluid volume leveling. In prior versions, pumps would pull the full 200 volume unless it wasn't possible to do so from the source. It no longer appears pumps are behaving this way, and that's probably the source of the problem.

[Kingdud]

Sorry, I forgot how many mods I was using. None of them are relevant to the problem, so I have made a modified map which shows the same behavior, but only uses a single mod (for a fluid void). The fluid void shows a slight improvement (660k/m vs 648k/m) but still shows there's a problem. Both with and without a pump before said void.

[tehfreek]

viewtopic.php?p=408852

[Dominik]

Yes, as in the link - we know pumps are not perfect now but it will be addressed later.
There should be no reason for it to change during 0.17 though.

[malventano]

So, this may not be a bug
...
I should be getting 720k water/minute, but production stats only shows 648k.

This appears to have actually been a bug, though I'm currently trying to convince the devs of this.

The issue relates to the fluid system change, where the pump fluidbox size no longer supports sustained transfers >6000/s. I've included the appropriate change as part of my Manifolds mod, and I ask that you try loading your map with that mod installed to see if your flow rates return to the expected values.