AMD's latest mainstream desktop platform boasts arguably the most potent two-chip combo in the industry. At the head, you've got an A-series APU powered by the latest Llano silicon, which offers four reasonably fast CPU cores backed by a DirectX 11-class Radeon that puts competing integrated graphics solutions to shame. Baby's got back, too. The tail end features a Hudson-based platform hub that's loaded with 6Gbps Serial ATA and USB 3.0 connectivity. No other tag team offers such a cutting-edge array of baked-in goodness, making this Lynx platform perfect for the next wave of small-form-factor systems.
If you want to roll your own mini PC, you'll be needing a Mini-ITX motherboard. Our first instinct would be to look to Zotac, which is largely responsible for reinvigorating interest in the decade-old Mini-ITX form factor. Over the past few years, Zotac has rolled out a number of attractive Mini-ITX motherboards based on the latest chipsets and sockets. Indeed, the company's Z68-ITX WiFi earned a TR Recommended award when we dissected it back in July.
As you've probably guessed, Zotac has cooked up a new Mini-ITX board built just for AMD's A-series APUs. The A75-ITX WiFi offers all the perks associated with the newest Fusion platform, plus additional wireless amenities. And it's not alone. The recent popularity of midget motherboards has attracted the attention of Asus, which has designed its own Mini-ITX home for Llano: the F1A75-I Deluxe. Naturally, we couldn't resist pitting these two contenders against each other in a featherweight cage match.
Zotac's A75-ITX WiFi motherboard
The Mini-ITX form factor is Zotac's adopted home turf, so it stands a better chance against Asus than one might expect given where the two companies sit among the multiple tiers of motherboard makers. Asus is the biggest name in the retail motherboard market, while Zotac is at best a second-tier player. Zotac made its name inside small-form-factor systems, and the A75-ITX is designed to fuel the next generation.
The board itself looks relatively sedate. Although the overall aesthetic isn't particularly eye-catching, Zotac deserves credit for deviating from the black-and-blue color scheme that has permeated the bulk of new motherboard designs.
Small-form-factor systems present particular challenges when it comes to component clearances. As you can see, the A75-ITX's various slots and ports are snuggled right up next to the CPU socket. To provide a better sense of how much room there is to spare, we busted out a ruler to measure a few key clearances.
There's only 17 mm of space between the CPU socket and the closet DIMM slot. Depending on your CPU cooler, that arrangement could complicate compatibility with taller memory modules. The VRM and chipset heatsinks put more distance between themselves and the socket, and they're only about 30 mm tall. Only the most overgrown CPU coolers are likely to restrict access to the PCI Express x16 slot located at the far edge of the board.
The more than three-inch gap between the socket and the x16 slot is densely populated, even if its inhabitants are relatively stunted. On the far left sits a front-panel USB 3.0 connector. Beside it, an AzureWave Mini PCIe card bestows the board with 802.11n and Bluetooth 3.0 wireless functionality.
Over to the right, we see Zotac is only taking advantage of four of the six SATA ports built into the A75 chipset. That should cover the storage needs of most small-form-factor systems, but the top-right port is a little too close to the CMOS battery. The vertically mounted battery is tall enough to interfere with the locking tabs on Serial ATA cables—including the ones that come in the box—so you'll want to keep a small, flat-headed screwdriver handy.
We can follow the wireless card's loose, looping wires all the way to the port cluster, where they're anchored to a pair of antenna jacks. The wiring is awkwardly bent around the heatsink fins it touches—not a big deal, but amateurish when compared with what you'll see on the next page.
With the exception of internal headers for a pair of old-school USB 2.0 ports, the rest of the A75-ITX's USB connectivity is of the SuperSpeed variety. Counting the internal headers and the six ports in the rear cluster, there are twice as many USB 3.0 ports as are available in the A75 chipset. Rather than relying on third-party controllers to supply the additional ports, Zotac splits the ones coming off the A75 using a pair of USB 3.0 hubs from Via. These VL810 hubs are capable of splitting one USB 3.0 port into four, but it's unclear which of the A75-ITX's ports stem from the hubs and which, if any, are linked directly to the chipset. We're still waiting on Zotac to explain how everything is connected.
For all four of you who want to build a Llano-based NAS box, the A75-ITX serves up a pair of Gigabit Ethernet ports backed by Realtek controllers. Realtek also provides the audio codec, an ALC892, which fuels five analog audio jacks and a digital S/PDIF output. If you're short an S/PDIF input on your speakers or receiver, multi-channel digital audio can be passed through the HDMI port by Llano's integrated Radeon.
Zotac ties the Radeon to DVI and HDMI outputs. A CMOS reset switch is tucked just to the left of those display ports in the rear cluster. The button might seem like a minor addition, but anyone who has ever tried to get at the CMOS reset jumper in a cramped Mini-ITX enclosure will definitely appreciate it.
Although the A75-ITX has one of those newfangled UEFIs, you wouldn't know it by using the thing. There's no mouse support, the graphical interface looks exactly like an old-school BIOS, and the array of tweaking options is limited. Short of an APU multiplier setting that's largely useless until AMD releases unlocked Black Edition versions of Llano, the UEFI is pretty much devoid of overclocking options. You can crank the memory clock to 1866MHz, but that's about it. Even the voltage options are extremely limited—in both scope and granularity.
Overclocking a small-form-factor Llano box probably wouldn't be wise. However, you're definitely going to want to tune that system's fan behavior to make it as quiet as possible. The UEFI doesn't do too poorly on this front, offering the ability to set a starting temperature threshold, plus starting and maximum speeds for the CPU fan. One can also switch the CPU fan into a manual mode locked at a static speed. Separate controls aren't provided for the system fan, though.