Which Slot Should You Use?

There are two types of SSDs: SATA and NVMe SATA uses an older interface with one designed around hard drives while NVMe is designed for flash memory

Yes that's the confusion! I read that manual and when I spoke to customer support, they said second slot is also Gen 4 Maybe they are

m2 vs nvme slot Two types of PCIe slot on an Asus H81M-K motherboard Various slots on a computer motherboard, from top to bottom: PCI Express x4; PCI Express x16; PCI Express

m2 slot mainboard On regular office and gaming PC motherboards, the slot closest to the CPU will most often be the one that has the highest bandwidth, but always check your