Here is what I've found on the board. ECS has somehow kept the SAS 6Gb/s ports (configured as SATA III) ports alive on their ECS X79R-AX5-Way Intel X79 Motherboard ShootoutSteven Walton | January 16, 2012
What's more confusing, ECS claims the X79R-AX 14 SATA ports with 10 connected to the X79 chipset, which is only supposed to support six. The board supposedly has six SATA 6Gb/s ports and four SATA 3Gb/s ports wired to the X79, but Intel's block diagrams clearly says the chipset supports two 6Gb/s ports and a total of six SATA ports -- two 6Gb/s and four 3Gb/s ports, in other words.
Intel's tech manager assures me that the X79R-AX's extra SATA ports must be connected to a third party controller, while ECS promises 10 are powered by the X79. ECS went on to say that Intel has removed (or merely hidden, as it seems) the X79's four extra SATA/SAS ports, but the Taiwanese motherboard manufacturer has managed to enable them on the X79R-AX. Very interesting.
To our knowledge, ECS is the only manufacturer to enable these four hidden SATA/SAS ports. The company says that not all hard drives will work on the four SATA 6Gb/s (SAS) ports, but we couldn't obtain a list of compatible drives, nor did we receive a detailed explanation on why some drives won't work, how the "hidden" ports were enabled or why Intel disabled them in the first place.
and... here is an article on the SAS 6 ports at legit Reviews:ECS Enables Intel X79 SAS Ports on X79R-AX MotherboardDan Stoltz | January 17, 2012
From ECS to Legit reviews on this topic
"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. 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..."