As with the X99-DELUXE, the X99-A has physical switches for XMP memory selection, enabling or disabling the EPU (Energy Processing Unit, a custom micro controller for power saving operation), and two levels of instant overclocking with the TPU (Turbo Power Unit) switch. You can see what’s probably the TPU micro controller in this image. I say “probably” because although ASUS used to label the TPU and EPU separately, on this board they’re both labeled “TPU”.
If you look just to the left of the EX XMP switch, you’ll see two jumpers. The lower jumper clears the CMOS, while the upper jumper unlocks higher CPU voltage settings. Even though this is not ostensibly an “enthusiast” board, the latter is a nice feature to have.
Between these three switches and the X99 chipset heat sink is the m.2 SSD socket. M.2 SSDs offer higher performance than even the fastest SATA-based SSD since they connect via a pair of dedicated PCI-E lanes. Note that using an m.2 SSD will restrict the third x16 slot to only x4 as the other lanes are needed for the SSD.
The X99-A gets by with a single SATA Express connector…
…but there’s another pair of Intel-powered SATA 6G connectors by the second USB 3.0 connector on the front edge of the board.
The gold Nichicon audio capacitors look pretty, and are normally found in high-end audiophile gear. Combined with the Realtek ALC1150 audio codec, the result is an onboard audio system so good that you shouldn’t ever feel the need for a separate audio card.
An 8-phase power system supports the CPU. Since Intel has moved much of the voltage regulation functions onto their modern CPUs, the elaborate 12, 16, and higher-phase power supplies we used to see in enthusiast motherboards simply aren’t needed any more.
Custom chips used on the X99-A include ASUS’ own Digi+ power control, the TPU (or EPU) micro controller on the components side of the motherboard, an ASMedia ASM1074 USB 3.0 hub, a Winbond BIOS chip, a Nuvoton voltage/temperature sensor-controller, and the EPU (or TPU) on the back of the board.
In the next section I’ll look at the ASUS X99-A BIOS.