Connectors and I/O
In total, ASUS equipped the Prime X299-A motherboard with eight SATA 6Gbps connectors, which have all been natively wired to the PCH. Furthermore there are two M.2 slots, where the first is located below the second and the third full-sized PCIe slot and the second M.2 slot can be found below the ATX power connector. If you want to use that particular M.2 slot you'll have to install the M.2 SSD perpendicular to the motherboard. We're not really a big fan of this solution and would wish for a another M.2 slot parallel to the PCB instead. With this motherboard you get three full-sized PCIe slots and all of them received metal reinforcements. The first two full-sized PCIe slots have been wired using eight lanes while the third, bottom-most, slot features eight lanes. With a 44-lane CPU, you can run 16x/16x SLI/CrossFire and 16x/16x/8x CrossFireX (3-way). Basically these are the standard options you get with any Intel X299-based motherboard, that does not feature a PLX chip. The placement of the PCIe connectors has been well thought. Furthermore we also see all the bells and whistles you'd ask for in the event of overclocking.
The ASUS Prime X299-A motherboard features a total of seven fan headers, which is more than enough to provide a high-end gaming rig with fresh air. A closer look at the pictures below shows where they have been placed. All six fan headers feature 4 pins and support PWM functionality. Therefore it's possible to control fan speeds from within Windows as well as the BIOS.
Back I/O Ports
- 1 x LAN RJ45
- 2 x USB 3.1 Gen 2 Type-A & Type-C
- 4 x USB 3.1 Gen 1
- 2 x USB 2.0 (1 Port USB BIOS Flashback)
- 1 x Optical S/PDIF out
- 5 x Audio jack
- 1 x USB BIOS Flashback Button