Valheim Wiki - System Requirements
Minimum
OSWindows 7 or newer
ProcessorIntel Core i5-2400 / AMD FX-8320
Memory8 GB
GraphicsNVIDIA GTX 660 (2GB) / AMD Radeon HD 7850 (2GB)
Storage10 GB
Recommended
OSWindows 10
ProcessorIntel Core i7-4770K / AMD Ryzen 5 1500X
Memory16 GB
GraphicsNVIDIA GTX 1060 (6GB) / AMD Radeon RX 580 (8GB)
Storage10 GB
Source: Official Steam store page, confirmed unanimous across multiple independent sources