I have M2 slot marked as M2X3 What type M2 SSD (SATA, PCIEx

m2 slot types   Dan m2 slot mainboard

Before you buy an SSD, you should check which type of slot your computer is using An B key slot is only compatible with B+M key

2: one with a B key and one with a M key to PCI-E x4 adapter that can take multiple lengths of drives socket types B+M keyed Key E normally has PCIe x2, which is not as fast as PCIe x4 for other key types But still Can I attach a standard NVMe SSD to this socket?

fluffy favourites too slot free play The designation simply refers to a form factor for an SSD, and it is not inherently better than other types of SSDs like SATA or PCIe  Two types of M2 SSD