Asus TUF series of motherboards has produced some corkers over the years, but with overclocking performance narrowing in most fields, it can be tricky to justify the extra cost of any premium motherboard over its cheaper mainstream counterparts. At £285, the latest addition to the TUF family – the Sabertooth X99 – certainly sports a premium price tag as well, but it justifies its cost with a plethora of additional features. For example, there’s an Android app that enables you to view the motherboard’s power status and view POST code displays by connecting your smartphone to a dedicated USB port on the I/O panel. It also sports arguably the best automatic fan control software available – Thermal Radar 2. This software enables you to control individual fan profile curves, or even match them with one of the included thermal probes. The software can also tap into Asus graphics card cooling fans. There are seven 4-pin fan headers too, so you can cater for most cases without needing fan-splitter cables
The Thermal Armor does present one or two issues when it comes to practicality though. For starters, the M.2 port is hidden underneath it, with a screw-fitted latch covering it next to the 1x PCI-E slot. Some of the ports can be a little fiddly to access too. That said, we were pleased to see that the M.2 port supports up to 110mm SSDs, while layout is generally very good, with all seven fan headers mounted on the edge of the PCB, for example.
It’s also clad in the usual plastic Thermal Armor found on previous TUF boards, and whether you like its appearance is down to your own personal taste, but at least you can remove it. However, in our opinion, the Sabertooth X99 is probably the bestlooking TUF motherboard we’ve seen, despite the Thermal Armor still making an appearance, along with beige-coloured ports and DIMM slots. It’s a beast of a motherboard and it weighs over 1.5kg too. This weight is mostly due to a large metal backplate that protects the PCB, and is connected to the rear of the VRMs with a thermal pad to aid cooling. A small fan is also included that you can attach to the Thermal Armor to aid cooling of the VRMs. Of course, a lot of the TUF ethos is about durability, so Asus makes a song and dance about the more durable
chokes and capacitors, while the motherboard itself includes numerous covers for expansion slots, DIMM slots and connectors to protect against dust. What’s more, the covers are black, so you can hide nearly all the beige details if you don’t like the look of them
Perhaps the Sabertooth X99’s most stand-out feature, however, is its next-gen interface support. Firstly, it has two USB 3.1 ports. If you remember when USB 3 hit the shelves, there was a distinct lack of compatible devices and the same is true for USB 3.1 at the moment. The new standard has, however, proved itself in testing, with our own sequential tests showing speeds of around 800MB/sec compared to around 400MB/sec for USB 3. The Asus Sabertooth X99 also supports all current NVMe Express storage devices, including the latest 2.5in SFF-8639 SSDs from Intel, some of which promise over 1GB/sec read speeds.
Three-way GPU setups are supported as well, although as with all X99 systems, your total PCI-E bandwidth will depend on your choice of CPU. The cheaper Core i7-5820K only has 28 PCI-E lanes and, as a result, the third slot can only offer up to 4x speed in three-way modes with this chip. Also, while a 40-lane CPU will allow for 8x speed in the third slot, this slot will be disabled if you use a PCI-E M.2 SSD. Thankfully, this situation will only be an issue for a very small minority of people.
The downside is that this performance comes at the price of power consumption. The SATA 6Gbps speeds were on the money too, with 550MB/sec read and 515MB/sec write speeds coming from our Samsung 850 Pro test drive. Meanwhile, the Sabertooth X99’s EFI was the usual slick Asus affair, and overclocking proved to be an easy task. Hitting 4.2GHz was simple, requiring a vcore of 1.28V with little other tweaking.
The stock speed benchmark results were mightily impressive, most likely due to the Sabertooth X99’s fairly aggressive CPU Turbo mode, which saw the CPU remain at the maximum Turbo frequency throughout most of our testing. It was streets ahead of all the other boards we’ve tested in our video encoding and multi-tasking tests, with the resulting system score being a good 9,000 points ahead of its nearest rivals.
We gunned for 4.3GHz, which we eventually managed to get stable, but not without a hefty vcore of 1.32V and a System Agent voltage of 0.95V. This overclock also saw the peak power consumption rise to 466W, although this isn’t the highest we’ve seen. Here, the Sabertooth X99 again made a strong showing in our benchmarks, gaining the highest video encoding score we’ve seen.