The quad-channel memory system with its 8 DDR4 memory slots forces the onboard power circuitry to the side of the giant CPU socket, rather than between the socket and the rear I/O panel. The components for the 8-phase power supply can be seen peeking from under the heat sink at the right side of this image. The heat sinks are low profile and there should be plenty of room for the largest air coolers.
In front of the PCI-E slots we see ASUS’ Turbo Power Unit custom micrcontroller…
…which we also see on the back of the board. ASUS says that one of these chips is actually the EPU power-saving controller, noting that these are programmable microcontrollers and that programming is what counts, not the label on the chip. Still, it seems odd.
As you’d expect in a high-end motherboard, the audio circuitry’s pretty nice, courtesy of an ALC1150 audio codec. ASUS says the shroud over the audio circuitry incorporates metal shielding to prevent EMI interference, and that the flashy gold capacitors are “audio grade”.
Looking at the lower edge of the board, we see the front panel audio connector, a power button, a reset button, a two-digit POST code display, a clear CMOS button, and a Trusted Platform Module connector. The rectangular white connector above the clear CMOS button is a connection for the external fan controller board.
Continuing along the edge of the board we encounter two USB 3.0 connectors, two USB 2.0 connectors, and the front panel connector. The 5-pin connector just above the front panel connector is where you’d attach the cable for the optional Thunderbolt card.
Above these are switches for PCI-E lane configuration (labelled “SLI/CFX”, and more on this in a moment), an EZ XMP switch, and the EPU and TPU switches. The latter three switches offer simple control of the performance and power-usage aspects of the board: flipping the XMP switch will cause the board to apply your memory’s eXtreme Memory Profile (if it has one); the EPU switch lets the system selectively power down or underclock portions of the board to save power when they’re not being used, and the TPU I II switch applies a mild or more aggressive automatic overclock to the system. If digging around in the BIOS isn’t something you find fun, these switches make getting a little extra performance a very easy thing to do.
But let’s take a closer look at that new switch:
One benefit of LGA2011 systems is their extra PCI-E lanes: depending on which Haswell-E CPU you get, you’ll get either 40 (from the top-end 5960X) or 28 Gen 3 PCI-E lanes from the processor, either of which are improvements over the paltry 16 lanes offered by LGA1150 Haswell CPUs. The X99 chipset still offers only 8 Gen 2 PCI-E lanes, though. But keep in mind that while the previous-generation LGA2011 systems had the same number of lanes, the Haswell-E CPUs PCI-E lanes are Gen 3, with twice the bandwidth per lane.
However, you can still run out of lanes, since more and more things use them. This switch allocates lanes between the three PCI-E x16 slots and the m.2×4 SSD slot. With the switch in the 2X position as shown above, a system with two video cards gives each card the full 16 lanes, as well as reserving four lanes for m.2 SSDs. A system with three cards would need the switch in the 3X position, which would run the graphics cards at x8/x8/x8 and enable the m.2 slot; alternatively, in the BIOS, you can choose to have this switch position set the graphics card slots to x16/x16/x8 and disable the m.2 SSD slot. Given that these are all PCI-E Gen 3 lanes, though, you’re not going to loose any graphics performance at running at x8, so you might as well accept the default and keep your m.2 options open.
Let’s take a look at the latest iteration of ASUS’ UEFI BIOS in the next section.