It's hard to say the exact system requirements, it heavily depends on which game you're playing.
If you experience too much lag, then changing to a lower resolution may drastically improve your fps.
These are the rough estimate system requirements for an PlayStation 4 game:
Right now the emulator works on Windows & Android.
System Requirements: (Note: these heavily depend on the game you play, but this should give you an estimate)
OS: Windows 7, Windows 8, Windows 8.1, or Windows 10 Processor: AMD Ryzen 3 1200 / Intel Core i3-6100 or higher RAM: 8GB Graphic card: Nvidia GTX 970 / RTX 2060 or higher Graphics card memory: 2 GB
OS: Windows 7, Windows 8, Windows 8.1, or Windows 10 Processor: intel core i5 3470 / amd fx 6300 or higher RAM: 16GB Graphic card: Nvidia gtx 1050 / Radeon rx 560x Graphics card memory: 4 GB