- last edited on by
ROGBot
Greetings. The Crosshair VI Extreme contains two M.2 slots and if you are installing only one M.2 as an NVMe boot drive, it leads to the question of which slot is most efficient for booting the OS? Here are pictures showing the two M.2 socket positions. The M.2_1socket on the right side of the image that is covered by the X370 heat sink accommodates M-key type 2240/2260/2280 drives. The M.2_2 socket at the bottom of the image that is not covered by the X370 heat sink accommodates M-key type 2240/2260/2280/22110 drives.
The M.2_1 socket can be placed in either SATA or PCIE 3.0 X4 mode, which is confusing to me because the PCIE 3.0 controller is in the Ryzen CPU while the SATA AHCI controller is usually in the mobo chipset, the X370. (What does it mean for an M.2_1 socket to be in "SATA" mode anyway?) The X370 does have a PCIE controller, but it is PCIE 2.0 and it controls the black X1 and X4 slots on the motherboard, so it cannot directly control the M.2_1 socket when that socket is in PCIE 3.0 mode. Can the M.2_1 socket be switchable between the CPU and X370 controllers, and if you switch M.2_1 to PCIE 3.0 mode, does it use the X370 chip as a "pass-through" to the CPU PCIE controller? Alternatively, the M.2_2 socket is only in PCIE 3.0 x4 mode and shares bandwidth with the PCIEX8_2 card slot which is under the control of the Ryzen 7 CPU. Additionally, the ASUS web pages indicate that you can install two NVME drives in M.2_1 and M.2_2 in RAID, so they would both be managed by the CPU PCIE controller, I would think. See this image from the specs sheet:
My inclination is that faster booting might occur using the M.2_2 socket because it directly uses the CPU PCIE controller, but I really don't know. The downside is that the M.2_2 slot can't take advantage of the X370 heat sink. Does anyone know if there would be a difference in boot efficiency between these two mounting options? It would be good for an ASUS engineer to comment. The manual does not offer enough information about this.
Thanks!
The M.2_1 socket can be placed in either SATA or PCIE 3.0 X4 mode, which is confusing to me because the PCIE 3.0 controller is in the Ryzen CPU while the SATA AHCI controller is usually in the mobo chipset, the X370. (What does it mean for an M.2_1 socket to be in "SATA" mode anyway?) The X370 does have a PCIE controller, but it is PCIE 2.0 and it controls the black X1 and X4 slots on the motherboard, so it cannot directly control the M.2_1 socket when that socket is in PCIE 3.0 mode. Can the M.2_1 socket be switchable between the CPU and X370 controllers, and if you switch M.2_1 to PCIE 3.0 mode, does it use the X370 chip as a "pass-through" to the CPU PCIE controller? Alternatively, the M.2_2 socket is only in PCIE 3.0 x4 mode and shares bandwidth with the PCIEX8_2 card slot which is under the control of the Ryzen 7 CPU. Additionally, the ASUS web pages indicate that you can install two NVME drives in M.2_1 and M.2_2 in RAID, so they would both be managed by the CPU PCIE controller, I would think. See this image from the specs sheet:
My inclination is that faster booting might occur using the M.2_2 socket because it directly uses the CPU PCIE controller, but I really don't know. The downside is that the M.2_2 slot can't take advantage of the X370 heat sink. Does anyone know if there would be a difference in boot efficiency between these two mounting options? It would be good for an ASUS engineer to comment. The manual does not offer enough information about this.
Thanks!
.JPG "Velcade"){kind=avatar}
