Thread scheduler resolution fix for GM:Studio and GM8.1
This hack works by providing a fake dll stub that sets the thread scheduler resolution to 1ms, providing a smooth framerate across studio and 8.1 games. The games are not patched, so it's possible to use with steam and it should also be fine for speedrunning communities. If you like my work, consider buying me a coffee!~
If you're making a game using 8.1 or Studio 1.4, rather than patching an existing game, consider using gmsched instead, as it's a much cleaner solution.
We've created a tool that automatically fixes issues in affected Game Maker versions: Debugger Helper
Alternatively, you can manually install by downloading DBGHELP.DLL and placing it next to the Game Maker 8.1 game or the Studio runner. Remember that some studio games are packed, so use a tool like 7z to unpack them (you should be able to see the game .exe, data.win and some miscellaneous data files). If a studio game is still packed it won't work. Or let Debugger Helper do it for you.
By default, in modern Windows, the thread scheduler resolution is about 15.4ms. This means that if a program tries to skip time to save power, it'll only get invoked again in the next possible interval of 15.4 milliseconds. A coarse resolution means threads sleep very imprecisely, leading to massive frame drops and stuttering in game maker games as they fail to present frames on time. By setting a finer resolution like 1ms, we make sure the game thread is woken up on time to present every frame.
The dll we're using as a hook isn't important for the games to run, so not much really. There are concerns about more power usage by the scheduler running more often, but since we're talking about games, it wouldn't really make much of a difference in the first place since this is expected for games.
Moreover, this tool does not help with 8.0 games or issues related to the infamous gm8.x "joystick bug", or out of memory crashes. If you still have problems with 8.0 and 8.1, consider patching them with gm8x_fix, as that resolves the scheduler and other issues mentioned. Additionally, Debugger Helper is capable of applying all the patches.