Is the ssd slot compatible with sata 3 ssd or only with

3 slots where most boards disable 2 of the sata ports, asrock disables the 3rd pcie slot in the case of the two boards you're looking

Supports SATA Gbs, SATA 3 Gbs and SATA 6 Gbs Dimensions : ca 1 x 67 pin key B slot Interface: SATA PCIe (2 or 4

sata m2 slot You would probably need to use the PCIe slot if you have one free, but I simply don't know if the bus is fast enough

sata 3 slot 3 x4 lanes of up to 4000MBs Not to say that speed is 2 SATA is just a complete wasted