Storage, ports and DIY-friendly features
The Z170-A's storage connectors are all clustered at the bottom right-hand corner of the board.
Here we find a SATA Express connector alongside four standard SATA ports. This layout gives us a total of six SATA 6Gbps ports, two of which are part of the SATAe connector that you see on the right. We mentioned that running the third PCIe x16 slot in x4 mode disables two of the SATA ports on the Z170-A. The affected ports are the leftmost two in the above picture.
South of the low-profile chipset heatsink is the Z170-A's M.2 port. This location lets the Z170-A support devices up to 110 mm long, and it could allow mini SSDs installed here to run cooler than on boards with M.2 connectors situated underneath PCIe x16 slots filled with power-hungry graphics cards.
Thanks to Z170's upgraded PCI Express connectivity, PCIe M.2 drives get four Gen3 lanes from the chipset. This gives storage devices up to 32Gb/s (4GB/s) of bandwidth, an impressive increase over the bandwidth provided to chipset-connected M.2 devices on previous generation boards.
SATA-based M.2 SSDs are also supported, but plugging one in means the SATA Express port can only be used with PCIe devices, because both ports share the same SATA connection to the chipset. A firmware configuration option specifies which port runs in SATA mode.
Another new feature of the Z170 chipset is support for RAID arrays across PCIe SSDs. These arrays are managed by Intel's drivers, and they can be formed from AHCI or next-gen NVMe SSDs. NVMe-based drives can be installed in the third PCIe x16 slot or the M.2 slot.
The Z170-A's rear port cluster is a mish-mash of old and new. Not only does Asus give us a VGA output and a PS/2 port—Model M owners rejoice—but we also have both Type A and Type C USB 3.1 ports courtesy of an ASMedia ASM1142 controller.
For buyers looking to tap into Skylake's integrated GPU, the Z170-A offers the aforementioned VGA connector, a DVI-D port, a full-size DisplayPort, and an HDMI port. These last two support DisplayPort 1.2 and HDMI 1.4b, respectively. Folks with discrete graphics cards don't have to worry about the onboard display outputs, of course.
The Gigabit Ethernet port is powered by Intel's I219V controller. Asus bundles its own traffic prioritization software with the Z170-A, called Turbo LAN. This utility aims to improve ping times when online games are competing with other applications for bandwidth. While packet prioritization is nice in theory, it doesn't help if the network congestion is occurring at some point outside of the PC.
Outside of the two USB 3.1 ports below the Gigabit Ethernet port, all other USB ports are connected directly to the chipset, including the two USB 3.0 ports below the PS/2 port and the leftmost two USB 2.0 ports. Four more USB 3.0 ports are available via two internal headers, as are four more USB 2.0 ports.
colorful graphical representation of all of that information:
Asus calls the Z170-A's audio implementation "Crystal Sound 3." The underlying audio codec is the familiar ALC892 from Realtek, backed by a TI R4580 amplifier and high-end Nichicon audio capacitors.
The codec chip used on the Z170-A isn't quite as fancy as the ALC1150 found on some pricier boards, but Asus has taken measures to improve the onboard audio in other ways. A pre-regulator is placed in front of the audio codec to minimize power supply noise. Left and right output channels are split between different PCB layers. Shielding is applied to both the codec and the analog traces. The TI amplifier chip's output can be routed to either the front or rear outputs in software. A special "de-pop" circuit designed to minimize popping noises during startup.
The Z170-A's analog audio output produces sound that my ears were happy to hear, with no unwanted noise under a variety of load and idle conditions. For those who want digital output from the Z170-A, DTS Connect can encode multi-channel digital output in real time. Another DTS component, Studio Sound, enables surround sound virtualization for stereo speakers and headphones.
This mobo is equipped with a number of builder-friendly features. First, a tick of approval for the Z170-A's socketed firmware chip. The board also supports Asus' excellent USB BIOS Flashback feature. Although it might not be used every day, USB BIOS Flashback lets you update the firmware with nothing more than a USB thumb drive and a power supply. That could save you from having to beg, borrow, or steal a supported CPU to flash the firmware for a newer chip.
A front-panel wiring block—Asus calls it a Q-Connector—makes the finicky job of wiring up these headers so much more pleasant. It sure beats fumbling with a flashlight in a dimly-lit case. Just below the front-panel wiring block, we can see headers to clear the CMOS, as well as the DirectKey firmware shortcut. DirectKey offers a convenient way to enter the UEFI by default without having to resort to furious mashing of the Del key. The great little DIY-friendly features stop at the I/O shield, unfortunately. Asus includes a standard stampted metal cover, which eagerly awaits its chance to slice your fingers.
Now, on to the Z170-A's firmware.