I have the titled motherboard with an i5 4460 CPU with the last bios update that was done. I have this same combo both for my Unraid server and my main Windows 7 PC.

There are 6xSATA, an M2, PCIe 3.0 x16, PCIe 2.0 x16(max x4), 2 PCI slots on this mATX board.

I am a bit confused about the M2 port. It is supposed to be capable of SATA and PCIe (only x2) mode and the literature states it shares bandwidth with SATA 5/6.

 

On my windows PC I have an M2 drive installed using SATA mode (my boot drive) but I am not using SATA 5/6.

On my Unraid system I am not using the M2 slot and have all 6 SATA ports occupied (1 Parity, 2 SSD cache, 3 Data). Have a second hand LSI 4i card on way to expand using the PCIe x4 slot. I have a RX 580 as GPU passed through in the x16 slot (obscures one PCI slot) and the second PCI has a satellite card in for my docker.

 

As I understand it I think I could have SATA 5/6 ports occupied and the M2 in SATA mode would still work but the bandwidth would be shared between M2, SATA5 and SATA6 as opposed to the SATA 5/6 ports being disabled. Or am I wrong?

 

If I was to add a new M2 SSD that runs in PCIe x2 mode to my Unraid System how does that impact everything else? Does it affect the SATA interface at all? Does it affect the other PCIe slots? I cannot find any information on this after trawling the internet so hoping someone here has a better insight. Thanks in advance for any help.

Insert any M2 ( SATA / PCIe ) will disable corresponding SATA.

Edited June 27, 20197 yr by Benson

OK thanks for the reply. I'm not quite convinced yet though. It is just the wording of sharing bandwidth that is confusing when it does not specifically state that it is an either/or situation. So even in PCIe mode you think it has to disable the SATA 5/6? So it not would really be using a dedicated PCIe lane but 2xSATA lanes instead if that is the case. So I don't really understand how it can be called a PCIe mode if is really a double SATA mode.

 

The motherboard manual mentions in bios that for the M2 slot you set a priority bandwidth to either M2 socket 3 or the SATA 5/6 interface. This is the reason I am thinking they are shared rather than disabled. On auto the system detects the first priority device PCie M2 > SATA mode M2 > SATA devices.

 

So if it is the case that nothing is disabled, just shared, there would not be a problem for me to have both the M2 slot and SATA 5/6 occupied.

Because chipset I/O can be config for different purpose, but only one function per port.

 

https://linustechtips.com/main/topic/681228-guide-pcie-lane-distribution-updated-112118/

 

As you have M2 onhand, you can try put to Unraid.

 

Edited June 27, 20197 yr by Benson

After much searching and reading, as others have had similar questions, I have come to the conclusion that the SATA5/6 ports must be disabled when using the m.2 slot. The wording used in all the literature though is ambiguous because it really only mentions sharing rather than disabling. You would think it an easy thing to do to correctly write manuals with this important information.