Yesterday I was on my spawn plot just running around enjoying myself when I started noticing incredible lag spikes. I believe these lags spikes are coming from 2 places: The Casino and the Item sorter sort of next to my plot at -125, -125.
A bunch of us got together to see if it was my computer lagging or if anyone noticed what was causing the issue. We all came to the conclusion that the item frames and or signs in the 2 locations above are the cause for the lag spikes.
Keep in mind my specs: i7 2600k, 24gb ram, GTX 1070 and also keep in mind that I tried multiple different settings, including how many chunks I decided to render.
My suggestion: Limit the amount of signs / item frames near spawn and/or discuss having some (or all) or these signs / item frames removed form these two locations.
If you want to reproduce the problem: Walk in the area of -125 -125 for more than 5 minutes.
Off the top of my head allocating more RAM, full screen windowed mode as MC used to crash if I alt/tabbed. Everything else I don't think I've touched other than bumping the render distance to 12, which I believe is overkill for MR anyway? Clouds off as I use a skybox in my resource pack, which is a 32x iirc
Only thing I really noticed was FPS drop to 100 around spawn, but that's not surprising with the amount of builds/redstone there.
Have you tried letting GEFORCE Experience optimize the game? Could help.