TO REMIND YOU AGAIN DEPENDING ON HOW MANY MODS AND HOW GOOD IS YOUR DEVICE, SO I RECOMMEND TO BALANCE YOUR MODlLIST WITH YOUR DEVICE

IF YOUR CPU HAVE CPU BOOST MODE THING, TURN IT TO HIGHEST IDK ABOUT AMD BUT INTEL HIGHEST IS "AGGRESSIVE" PLS DO MIND IT WILL LIKELY HEAT UP BIGTIME UNTIL 95° C.

EVEN THEN ITS SAFE CONSIDERING ITS TERRARIA. BUT STILL ALWAYS KEEP THERMAL PASTE IN CHECK.

1) right click tmod on steam library and click properties














2) on launch options add /gldevice:OpenGL "-high -malloc=system -USEALLAVAILABLECORES -nomansky +mat_antialias 0" also turn off steam overlay

/ command is for using OpenGL instead of DirectX it seems tmod have problems with DirectX
"" commands is for fully allocating cpu to your game, again if you have low end cpu might not a good idea to add this

1) open your task manager, and click arrow down on DOTNET.exe and right click terraria and then click go to details

2) right click dotnet and set priority to high

OPTIONAL = set affinity and uncheck cpu 0 (it seems this trick no longer works, i tested and got lower fps. someone smarter than me please test. last time it works for me is 4 years ago)

this one was found by oliver
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=2997062221

tldr
go to your tmodloader game folder and edit tModLoader.runtimeconfig.json using notepad++ recommended and change DEFAULT_STACK_SIZE based on how big is your RAM 6400000 (6.4MB /thread) is a safe number for 8gb and up. you can test your limit if you have 16GB and even higher. like 10000000 (10MB/thread).

if you are desperate make graphic setting all low and off

for mods i recommend nitrate and high fps support
if you are desperate install lag remover and no more light projectile

in high fps support you can try to turn on custom tick in the mod config
and about 90-120 is good for increasing fps. but itll most likely will crash the game so your choice.