Two can install a Windows M.2 drive and another M.2 drive for all other components.
Two can install a Windows M.2 drive and another M.2 drive for all other components.
I'm setting up new PCs for the past eight years. I own an MSI Mag B550 Gaming plus motherboard that supports two M.2 slots. I want to know the best way to install drives. One should be the boot drive for Windows, the other for all data. I'm considering the WD BLACK SN770 M.2 2280 250GB for the Windows drive and the WD BLACK SN850 NVMe M.2 2280 1TB for everything else. The rest of the components include a Ryzen 7 5800X3D, MSI Ventus RTX 3050, GDDR6 DDR4 memory, G.Skill TridentZ, and other parts.
Just set up Windows on the M.2 you need. The system will only start from that drive with Windows installed. Everything else is disregarded. I suggest you place the main SSD in the nearest slot to the CPU. Once Windows is installed, add the other SSD later. This prevents Windows from being placed on the wrong drive. If the drives differ in size, it matters. Install Windows on the one you don’t want it on first. You’ll notice in the installer which drive is larger.
You have two Gen4 drives but only one PCIe4 slot available. Both are decent, but the SN850 performs slightly better. It would be best to use the Gen4 slot for your boot drive, making it impractical to find a suitable solution here. Consider using the 1TB SN850 as the Gen4 boot and game drive, while assigning the SN770 to PCIe3 for less demanding tasks.
During the setup of the windows installation, you'll need to choose the appropriate drive for installation. It will display available drive capacities so you can select the best one. Once done, the system will start from the SSD that already has windows installed.