Asus understands that a user paying for the PEX8747 bridge will probably use it, and smartly leaves out the fifth slot that would have stolen the bridge’s lanes. The Z87-WS also lacks Thunderbolt, allowing Asus to remove two controllers (the Thunderbolt controller and PLX Technology's PCIe 2.0 bridge) compared to several of its competitors. Buyers who don't need those features are rewarded with a $45 price reduction compared to ASRock's board on the previous pages.
Also missing from this reduced-price model are a couple of USB 3.0 hubs, which means that more of the remaining ports get full bandwidth. On the plus side are two eSATA ports with their own controller, two additional USB 2.0 ports on the I/O panel, and no reason to complain about any missing antenna connectors.
What appears to be a CLR_CMOS button is actually used for an Asus-exclusive feature called USB BIOS Flashback. A custom IC allows the board to update its firmware from a thumb drive with nothing more than a power supply attached. This is particularly useful when pairing motherboards that've been sitting in inventory a while with brand new CPUs, since the old BIOS often doesn't recognize the new CPU. I recently watched a technician use the feature to recover from a bad flash, as I listened to his call with Asus tech support.
The extra four internal SATA 6Gb/s ports (for a total of ten) are fed by a two-lane PCIe-based controller for added bandwidth compared to ASRock's board, which helps fulfill the Z87-WS’s “workstation” theme. Asus expects this board to be fully loaded with devices. The only sharing necessary is for mSATA, which disables one of the port connectors when it's populated.
Layout highlights include a secondary EPS12V input to support additional CPU current when overclocking, a second status indicator panel to further aid diagnostics, an internally-mounted external USB 2.0 port for ReadyBoost fanatics, a front-panel IEEE-1394 header for users of old scanners and digital cameras, and a front-panel audio header that’s been moved approximately one inch forward from its traditional rear-corner location. Asus appears to understand that the cables of many cases are too short to reach the corner, and compensates accordingly. Bravo!
The company is also fairly proud of the way it supports end users, and likes to remind us about its MemOK memory underclocking button (to assist re-configuration), DirectKey button (to boot directly to UEFI), EPU mode switch to allow auto-underclocking for energy savings, and TPU mode switch that enables a slight (ratio-based) to moderate (ratio- and BCLK-based) overclock for enhanced performance.
In addition to its ten SATA 6Gb/s cables and four-, three-, and two-way SLI bridges, the Z87-WS includes breakout plates for nine-pin serial port, USB 2.0, and IEEE1394 FireWire.