Hatsune Miku: Project DIVA Mega Mix+ was originally designed for consoles with limited OS-level multitasking support, and as such, the game's engine does not react well to frequent context changes on the CPU threads it occupies. To help alleviate this problem, one can try to increase the priority the game launches with to give it as much continuous CPU time as possible. This usually helps more the higher one's processor core count is due to the operating system scheduler having more room to avoid interrupting the higher-priority thread the game is configured to run on.

Note: Only edit the system registry if you are completely aware of what you are doing. Failing to follow the instructions in this guide correctly may lead to unintended consequences, including system instability and potential loss of data.

1. Open the Registry Editor (WIN+R -> regedit) (fig. 1)

2. Navigate to Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options by pasting the key address into the navigation bar at the top and pressing ENTER. (fig 2.)

3. Create a new registry key called DivaMegaMix.exe under Image File Execution Options. The purpose of this key and similar ones is to define the default execution behavior of specific applications, including the performance mode they launch in. (fig 3.)

4. Repeat the process explained in the previous step, but this time, create the key PerfOptions under DivaMegaMix.exe. This is where the application priority settings will be stored.

5. With PerfOptions selected as the current key path, create a new DWORD value under it and rename it to CpuPriorityClass. (fig. 4)

6. Modify the CpuPriorityClass value as follows with the following hexadecimal values to set the game's multitasking priority upon launch:

• High - 3
  
• Above Normal - 6
  
• Normal - 2 (Default)
  
• Below Normal - 5
  
• Low - 1

The higher the priority, the lower the frequency of gameplay-interrupting stutters will be. This may, however, cause the performance and stability of background applications to degrade, so try setting this value to Above Normal if High is giving you problems. (fig. 5)

7. Restart your computer.

Forcing the game to display as a borderless window might help stuttering issues on high refresh rate monitors, as the game's internal framerate limit (~64 Hz) is slightly higher than that of the 60 Hz display mode the game forces while set to fullscreen. Set Display Mode to 'No Frame' under the game's display settings: