Asus' Sabertooth 990FX motherboard
For years, it feels like motherboard makers have been compelled to differentiate high-end designs by piling on integrated peripherals and adding more extremeness to overclocking features. The thing is, modern mid-range boards offer more than enough expansion slots and ports to meet the needs of the typical enthusiast. The very same boards also tend to have enough overclocking headroom to cover air-cooled exploits, leaving most of us with little incentive to upgrade to something fancier.
Asus took note, and last year, it introduced a new family of TUF-series motherboards bearing the Sabertooth name. Designed for professionals, this line eschews the usual excesses to focus on component quality and thermal management. After watching Intel's X58, P55, and P67 chipsets get the TUF treatment, AMD fans finally have one of their own: the Sabertooth 990FX.
Like the rest of the family, the 990FX is draped in earthy tones that wouldn't look out of place in a camouflage print. The army aesthetic walks a fine line between being distinctive and perhaps a little bit dull, but it plays nicely with the chunky heatsinks and really suits the board's utilitarian personality.
As you can see, Asus hasn't bothered with the Thermal Armor cooling shroud that appeared on the Sabertooth P67. Good riddance. The armor is supposed to direct airflow to cool board-level components, but we found that it can have the exact opposite effect with typical system configurations. To help users fine-tune their own cooling solutions, the Sabertooth 990FX is equipped with no fewer than 10 temperature sensors covering everything from the CPU to the power regulation circuitry and USB 3.0 controllers.
While this slew of temperature sensors is a relatively new addition to the TUF arsenal, Sabertooth mobos have always had a penchant for exotic electrical components. Most high-end motherboards do these days. Unless you're familiar with the intricacies of capacitor chemistry, it can be difficult to tell which motherboard is really using the best parts. Asus makes its case with a laundry list of military specifications met by the Sabertooth's capacitors, chokes, and MOSFETs. Some of those standards are more applicable than others to life inside an enthusiast's PC, so it's hard to get too excited about the fact that Asus claims compliance with more military specs than its competitors. I'm far more convinced by the five-year warranty, which suggests a level of confidence in the board's long-term reliability that's unmatched in the industry.
The Sabertooth's socket looks a little crowded thanks to the close proximity of VRM and north-bridge heatsinks. Fortunately, the heatsinks stand just 29 mm tall, so they shouldn't conflict with too many aftermarket CPU coolers. You may not be as lucky with taller memory modules. The DIMM slots sit just 20 mm from the socket, and AMD's retention bracket doesn't allow coolers to be rotated in 90-degree increments to avoid clearance conflicts.
Drifting south gives us a good look at the Sabertooth's internal expansion options. The light brown PCIe slots run in a dual-x16 configuration, and the dark brown slot can be added to the mix in an x16/x8/x8 setup for three-way CrossFire or SLI. With only four lanes of bandwidth, the black PCIe x16 slot can't participate in any of that multi-GPU madness. There wouldn't be enough room for a fourth double-wide graphics card, anyway.
To the right of the expansion slots sit two rows of Serial ATA ports. The ports don't go right to the edge, providing a little more clearance for cramped enclosures that put the hard drive cage right next to the motherboard tray. As you might have guessed, the brown ports are connected to the chipset, while the black ones are linked to an auxiliary JMicron controller.
The JMicron controller is a 3Gbps model and nothing special. It's one of a pair, with the second chip feeding a couple of eSATA ports in the rear cluster. One of those ports has integrated USB power, while the other must go without. You're probably more interested in the USB 3.0 ports, though. There are two SuperSpeed ports at the rear, plus an onboard header for two more.
Like just about every other high-end motherboard, the Sabertooth has integrated audio fed by a Realtek ALC892 codec chip. Asus also relies on Realtek to provide surround-sound virtualization for stereo speakers and headphones, which can be enabled through the audio control panel. Surround virtualization is a nice little extra, but we'd rather have support for real-time Dolby Digital Live or DTS encoding. Such a feature would allow multi-channel game audio to be passed to a compatible receiver or speakers over a pristine digital connection that completely bypasses the motherboard's DAC.
The legacy BIOS we've been living with for ages is being phased out in favor of UEFI. This next-gen firmware interface is a huge improvement over its predecessor, offering native support for hard drives larger than 2.2TB alongside perks like mouse input and fancy graphics. Of all the UEFI implementations we've seen thus far, Asus' is easily the best. The EZ interface has some graphical flair but offers far too little control for real tweaking. However, the advanced mode, pictured above, layers just enough eye candy over a familiar layout that's very responsive and easy to navigate. The mouse integration works well, and you can even use the wheel to scroll through the various options.
Beneath its slick GUI, the Asus firmware has all the options you'll need to adjust clock speeds, to unlock disabled cores, to tweak memory timings, and to adjust voltages. Those features are old hat by now, but good fan speed controls are still hard to find. Asus does a good job on that front, serving up easily configurable, temperature-based fan speed controls for the processor and system fan headers.
If you'd rather tune your system from Windows, Asus' AI Suite software has you covered. Of particular interest is the Thermal Radar app, which is unique to the Sabertooth family and adds and extra layer of temperature monitoring and fan speed control. My old-school sensibilities still prefer such things to be handled independent of the operating system, but it's nice to be able to tweak various settings without rebooting into the UEFI.