Question 1

Why?

Accepted Answer

I would say that some people prefer having more of a 'storage' based system.  Plus, some smaller ITX boards are coming in with M.2, but perhaps only two SATA ports.  This would allow an ITX board to host 7 SATA drives (1 boot, 6 more in a ZFS array) while not needing a full ATX board.

Question 2

if this is an X4 pcie lane stick. how can there be more then 4 sata connections?

Accepted Answer

It has a SATA controller built in, and uses the PCIe connections to make the connection to the rest of the system.  So the SATA controller just appears to be just another 'add in card' as if you had plugged it into a regular PCIe slot.

Also, it's a x2 connection, but if you're connecting regular spinny hard drives, you'll probably never saturate the link unless you have a ZFS array with 4-5 drives on it as a regular HDD might do 100-150MB/sec maximum data transfer.

Question 3

Will this work on a PCIe Gen 2 host controller (an ARM SBC) or is the host required to have PCIe Gen 3?

Accepted Answer

The card has a 2-Lane M.2 PCI-Express 3.0 interface (B and M Key) and complies with PCI Express Base Specification Revision 3.1a.

Questions & Answers