The PS2 emulation can be resource-intensive. What is your hardware configuration?
Minimum (most games will be unplayable slow):
-Windows 7 / Linux OS 18.04 or newer (Ubuntu/Debian/Arch or other distros)
-CPU: Any that supports SSE2 with PassMark Single Thread Performance rating near or greater than 1600 + 2 physical cores with hyperthreading.
-GPU: PassMark G3D Mark rating around 3000 (GeForce GTX 750), 2GB VRAM, Support for: Direct3D10, OpenGL 3.x.
-RAM: 4GB RAM
Recommended:
-Windows 10 (64-bit) / Linux OS 19.04 or newer (Ubuntu/Debian/Arch or other distros)
-CPU: Any that support AVX2 with PassMark Single Thread Performance rating near or greater than 2100 + 4 physical cores with(out) hyperthreading.
-GPU: PassMark G3D Mark rating around 6000 (GeForce GTX 1050 Ti), 4GB VRAM, Support for: Direct3D11, OpenGL 4.5.
-RAM: 8GB RAM