Asus is so excited about SATA-Express (and its potential for differentiation) that the firm developed its own “Hyper Express” drive enclosure to leverage two mSATA SSDs against the new interface. We could have simply configured a couple of our own 2.5” SSDs in RAID using the chipset’s native interface, but that would have required two 2.5” drive bays.
Lacking added-in SATA or USB controllers, the Z97-A places four of the Z97’s six USB 3.0 ports on the I/O panel along with two of the chipset’s USB 2.0 ports. Higher up that panel are DisplayPort, HDMI, VGA, and DVI-D outputs that interface with the processor's GPU, which can drive three independent monitors.
The two PCIe 2.0 lanes saved by not adding a bunch of extra controllers are instead sent to the bottom PCIe x16 slot. I wouldn’t recommend using that slot for any sort of multi-GPU array, though it's still suitable for lower-bandwidth applications like building a display wall or even dedicating an older board to PhysX acceleration.
In spite of its relative simplicity, the Z97-A does eventually run out of PCIe lanes as it's filled with devices. The M.2 slot, for example, uses the same lanes as the two PCIe x1 slots, and that’s probably why Asus disables M.2 by default. Focus instead shifts towards keeping the two PCIe lanes of SATA Express open, since the company wants to be on the leading edge of SATA-E's development.
Asus-exclusive features like TPU (automatic overclocking), EPU (energy-saving underclocking), and MemOK (stability-enhanced memory setting) are still addressed by on-board buttons and switches. But Asus adds one more firmware-modifying piece of hardware in its EZ-XMP switch. New builders who might be afraid of UEFI menus can now enable this overclocking technology without losing their nerve, and commercial builders can enable full memory performance without concern that their customers might reset it.
The Z97-A includes four SATA cables, an SLI bridge, and some front-panel connector extenders that ease the bundling of loose cable ends (such as Power, Reset, and LED).