Gigabyte's GA-H170-D3HP is another ATX board with plenty of open space and easy access to a variety of connectors. It is the only board in this round-up with a USB 3.1 Type-C connector on it. Gigabyte says that its USB 3.1 controller gets a pair of PCIe Gen3 lanes, giving it up to 16Gb/s throughput, compared to 10Gb/s throughput if a pair of Gen2 lanes are used. The onboard M.2 connector is compatible with both SATA and PCIe connectivity. This board supports DDR4 only.
In the box, you get the board, a driver CD, a pair of SATA cables, an I/O backplate and a rather thin 8-1/4-inch x 5-1/2-inch staple-bound manual. It is so thin because it is English-only. As a result, it can be coerced to lie relatively flat. You also get a "G-connector," which accepts all of your front-panel jumpers and then allows them to be plugged en masse into their pin headers. Unlike Asus' similar Q-connector, it makes no electrical connection from the pins to their headers, but instead holds them all in the correct position to be directly attached. It is definitely convenient.
The audio codec is a Realtek ALC1150, by far the best in this round-up. It has up to 115dB S/N on its output and, if I'm reading the data sheet correctly, 110dB S/N on the input. This is pro-quality, so despite this board's large size, these showings would otherwise make it a nice choice for HTPC use or other audio work.
Although there are no display or diagnostic LEDs on the H170-D3HP, the audio circuitry is surrounded by LEDs, which can be set to a number of modes, including steady, pulsing, or beating to whatever music or other audio is playing.
Gigabyte's BIOS is crisp and clean, seen on this main screen and the status screen:
There were no functional options to overclock the i5-6600K on this board, just as on the other examples in this round-up.
The layout is open, and nothing is occluded, with the possible exception of the battery, but only if the second PCIe x1 slot is used. The SATA Express and SATA 6Gb/s ports are on the front edge to the left, facing forward, so even the longest graphics card(s) will not interfere with them. The eight-pin CPU power connector is on the right edge just behind the VRM heat sink there, but the latch faces rear so there's plenty of finger room. So far, this is the only motherboard I have seen with two USB3.0 connectors. They are side by side to the left of the ATX power connector on the front edge. These connectors, as well as all other connectors along the left edge (audio, com, thunderbolt, TPM and USB2.0) are box-style, which is more secure. The fan headers are not; it is worth noting that although they are all four-pin, only the CPU fan header supports a PWM fan. All others have a different pinout, with the sense wire in the location needed by three-pin fans.
The front-panel connector, in the front left corner, is not only color coded, but also comes with that "G-connector," which allows all front-panel leads to be pre-positioned, then attached all at once. I prefer this to the Asus "Q-connector," because this method does not introduce an additional point where the leads (typically all of them at once) can be accidentally disconnected.
OK, time for the numbers. Many are typical, but a few stand out. Let's take a look at the test results.