When Intel envisioned the X79, it planned to give it these four SAS channels. Unfortunately, due to what was described as “unreliable performance”, the company changed the specifications at the last minute. The result was that the X79 ended up with the same SATA port loadout as its predecessor P67 (four SATA 3.0 Gbps and two SATA 6.0 Gbps).

Now, it has been discovered that at least one motherboard, from ECS, features those four SAS ports that Intel decided were too unreliable. Legitreviews discovered that the X79R-AX sample had SAS ports wired to the PCH.

They also found that the firmware of the SAS raid controllers, and the drivers, could enable and use those ports, assuming they were set to active in the UEFI setup program (BIOS).

In its reply to Legitreviews questioning, ECS explains that it had already finalized its motherboard design when Intel suddenly decided to cover up the whole SAS issue.

It doesn't guarantee that the ports will work well but at least they are there.

“As to SAS labeled, it’s because originally Intel was going to support SAS connection on X79 chipset, but they hid this function in the end. However, since our MB layout already designed for this support, we decide to keep it,” the statement says.

“Due to Intel stopped on the project, so it’s hard to guarantee 100% compatibility on every SAS device, we have to keep it low profile as just more SATA ports to promote it (even though in our test, most SAS storage are workable on these ports). It’s indeed supported by Intel X79 chipset, even though Intel doesn’t announce to support either disable the function, the function are still in the chipset.”