Marathon Wiki - System Requirements
Minimum
OSWindows 10 64-bit
ProcessorIntel Core i5-6600 / AMD Ryzen 5 2600
Memory8 GB
GraphicsNVIDIA GeForce GTX 1050 Ti (4GB) / AMD Radeon RX 5500 XT (4GB) / Intel Arc A580 (8GB, ReBAR on)
Storage—
Recommended
OSWindows 10 64-bit
ProcessorIntel Core i5-10400 / AMD Ryzen 5 3500
Memory16 GB
GraphicsNVIDIA GeForce RTX 2060 (6GB) / AMD Radeon RX 5700 XT (8GB) / Intel Arc A770 (16GB, ReBAR on)
Storage—
Source: Official Steam store page, confirmed unanimous across 6+ independent sources