Question about render speed to expect

[michaelblight]

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Issue Description:
A question rather than a bug. Does the rendering slow down over time? I'm doing a radius of 5000, and initially it was coming out with a message of the next 100 fairly quickly, but now it says tiles rendered 3700msec per tile and 3800msec per render. I've restarted the server and given the VM 8 cores of an i9 and (I think) increased the tiles-rendered-at-once to 8 and set the boost to 3 for the radius. Some explanation on what to expect and tips on improving the rate would be helpful (I assume lores would speed things up, but I have plenty of storage so don't care about that aspect). Maybe these are expected numbers, but they started 10x lower and other posts seem to be much lower too.

EDIT: I cancelled the render and did another with radius 500 and now it's doing 200msec per tile, but then I cancelled that one and did another of 600 radius elsewhere and it's back up to 3500msec per tile, so I'm not sure what this is telling me.

• Dynmap Version: Dynmap-3.7-beta-6-spigot
• Server Version: 1.21-40-master@b45d9b6
• Pastebin of Configuration.txt: https://pastebin.com/5SETL3z2
• Server Host (if applicable): Self-hosted
• Pastebin of crashlogs or other relevant logs: NA
• Other Relevant Data/Screenshots: NA
• Steps to Replicate:

[X] I have looked at all other issues and this is not a duplicate
[X] I have been able to replicate this