https://mods.factorio.com/mod/quick-adjustable-inserters/discussion/66210456ed65ae039addc3f8

I have seen that mod's code and so far its precision remains inferior w.r.t. the inserter itself, the expanded number of pickup/dropoff targets notwithstanding. My code is licensed as public domain. It's up to JanSharp whether to benefit from it.

If you feel like Inserter Throughput is imprecise, feel free to elaborate.

I recently did a production with modules for which I needed to feed sand at about 21 per second. I put in a Inserter, changed its input and output points and your mod indicated 26.67/sec. Watching this machine work I saw that there was not enough sand in the input, I turned on the throughput display from the Quick Adjustable Inserters mod and it showed that the Inserter had a throughput of ~17.094/s and when I put a second Inserter with the same setting the machine had enough sand in the input

What mods? What inserter? What belt? What angle? What stack bonus? How do I reproduce this? An image would be great, too.

What does the measuring tool say about that inserter?

Space Exploration + Krastorio 2, Stack inserter, belt 90 item/sec, stack bonus +11

https://i.imgur.com/jt0Cq4N.png

Thank you, I will check it out.

I looked at this and it's the eternal problem of picking from belt. I even note it in the mod description here on the mod portal that the value for picking from belt is approximate. Though I will give you that in this case the discrepancy is very large.

For now, I have no idea how I will improve precision, or even if I can. By the way, while testing this I have also looked at the other mod's numbers and they are just as wildly off. Even worse in the most common case of inserter perpendicular to belt.

Remember, when all else fails, you can always use the measuring tool (/it-stopwatch) to measure the inserter's actual, live performance.