Not a bug
BYOND Version:514.1552
Operating System:Linux
Web Browser:Chrome 90.0.4430.72
Applies to:Dream Seeker
Status: Not a bug

This is not a bug. It may be an incorrect use of syntax or a limitation in the software. For further discussion on the matter, please consult the BYOND forums.
Descriptive Problem Summary: In projects like SS13 and Eternia, the internal functions of sendmaps() puts heavy CPU strain on the server. Roughly 1% per player.

With Eternia in particular the game's own functions only account for less than 5% of the CPU usage at any time, but sendmaps() comes in staggeringly high (95%+ during peak times). This is all internal and lacks any profiling data at the present moment until 514 expands on that, which I'll then update this thread with. Maybe others (SS13?) can use this to help figure out the problem area/s.

Did the problem NOT occur in any earlier versions? If so, what was the last version that worked? I think this has always been a problem to some degree, but maybe it's been made worse in recent releases? Hard to say. We likely did something on our end to exacerbate the problem where it became noticeably problematic, because our BYOND version had not been updated in a while when we first noticed the server choking. Attempts at debugging and figuring out what have come out short over the past month.

Lummox JR resolved issue (Not a bug)
This isn't really a bug, just something to look into more. It's going to depend heavily on the individual project.