NOTE - My issue affects all versions! Not just the snapshot.

Due to the final upload limit, I'm having to link to my video showcasing the issue: https://youtu.be/5Ssg2H1Z6EE

Specs of my PC are in the F3 screen I show.

For more context, I've had this survival world for 2 years... and the lag has progressively gotten worse. I thought it was entities causing lag but clearly it's not (I show that in the video)

I fly about 500 blocks away from my home base, and boom... FPS goes back up. Not a clue what the issue is.

I'm more than happy to provide you with more information... I don't experience game crashes or anything - it's literally just constant FPS drops... on SMP servers I get 200+ FPS easily... this issue seems to be very specific to this world so I'm not sure what's causing it.

Thank you for taking the time to help!

WORLD DOWNLOAD(as requested by violine1101): https://www.mediafire.com/file/zrfjg5nqmxd9kf7/The+Minecraft+Venture+-+Metricate+Mojang+Upload.rar/file

NOTE Go into creative and teleport to X: 33 Y: 73 Z: -26 for my main area.