ASRock Z87 Extreme9/ac
ASRock hides its two Thunderbolt interfaces under four USB 3.0 ports, maintaining enough room to stick a CLR_CMOS button next to one of them as well. The full-sized DisplayPort connector passes an external signal through to a Thunderbolt port; the HDMI connector can be used for another display.
Both GbE ports interface with Intel controllers to support teaming mode, and ASRock also adds Broadcom’s 802.11ac-capable mini-PCIe card for wireless networking. Those are features that could make the Z87 Extreme9/ac perfect in an enthusiast's principal workstation. We only seem to be missing antenna connectors on the rear I/O panel...
Instead, we get a plastic-faced 5.25” adapter tray, which replaces the firm’s familiar 3.5” USB 3.0 bay adapter, to host internal wireless antennas in addition to a pair of USB 3.0 ports. The bay adapter we knew so well could take a 2.5” SSD internally. In this version, it's able to accept a pair of solid-state drives. But if you want to swap out the internal antennas for high-gain or directional alternatives, you'll have to find yourself a slot adapter for the back of the board. This shouldn't be an issue unless you're fighting for more range.
The second x16 slot is wired directly to the CPU; using it bypasses the PEX8747 PCIe 3.0 bridge and all four corresponding x16-length slots. Though we see four dual-lane pathway switches beneath that slot, ASRock tells us that there's no way to go CPU-direct for x8 and x8 two-way configurations. If you want to use two cards, you instead need to go x16 and x16 using PLX Technology's switch, and slots one and four. The company's bundled SLI bridge supports that spacing arrangement.
Other layout features include a second eight-pin EPS12V connector to feed extra current to the 12-phase voltage regulator (if desired), a second front-panel USB 3.0 header behind the first header at the front edge for easy four-port front-panel configuration, an extra four forward-facing SATA 6Gb/s ports (totaling 10), a second replaceable BIOS I/C, and an extra USB 2.0 port that fits external drives.
Other than the lack of external Wi-Fi antenna connectors, the only insurmountable layout problem is a front-panel audio header that’s a little too far back in the bottom-rear corner to fit the short cables of some cases.
My assumption when I started writing this story was that once the pieces were in place to support three-way SLI, accommodating four cards should be easy. ASRock's Z87 Extreme9/ac doesn’t include a four-way SLI bridge however, instead requiring you to connect the first card to the second, the third to the fourth, and the fourth to the second using separate bridges. This arrangement is illustrated in the company's user manual.
What you do get is a three-way SLI bridge, ten internal SATA cables, and the previously-mentioned bay adapter, which includes two front-panel USB 3.0 ports, an internal Wi-Fi antenna, and support for up to two 2.5” SSDs.
