We've seen this one before and on that note have rejected this one before however new evidence has finally shown what causes this issue.

Power supply beams cause massive framerate drops if they are docked to a ship

So if you have docked generators you will have massive framerate drops

However this isn't due to the amount of beams it is only due to the ship being docked

In a test myself and my friends did it would seem the same amount of generators undocked floating in space hitting a ship cause no framerate issues at all

However docking them to the ship floating out in space causes the issue

My friend dropped from 400 FPS to around 41 FPS and I dropped from 200 to 10 FPS

Here is the blueprint we used. Please note this ship is only 6 blocks. This issue is not dependant on size of the generator however its better to test with smaller ones to stop a possible framerate issue from it being too large.

Now the steps to reproduce

In our test we used 34 generators so first you will spawn 34 generators with this blueprint and see that no issues occur

Then move a ship in front of the spawned floating generators so that the power supply beams hit it (within the range of the beam) you will also note this has no impact on framerate

Now dock all of those generators to the ship (all 34 of them) and you will note your framerate just died.

The more you dock the bigger the issue even though floating out in space giving power to a ship also floating out in space has no impact

This is not an issue with the raw amount of beams only when docked is this issue really noticeable (And it is REALLY noticeable)