ASUS X99-A/USB 3.1 LGA 2011-v3 Intel X99 USB 3.1 USB 3.0 ATX Intel Motherboard

Pros: These are the things I like about this MB:
Rock solid performance.
Includes dust covers for unused SATA, USB, expansion slots, etc.
Supports NVME (including as a boot drive) out of the box.
Rock-solid MB with the TUFF armor.
ASUS provides a lean set of useful utilities, including USB 3 boost for UAF drive support.
USB 3.1.

Cons: Things I didn't like so much...
Doesn't include the ASUS five-way auto overclocking utility.
M.2 slot conflicts with 2nd graphics card
Doesn't have light green plastic anywhere on like the X79 version did (this is purely subjective on my part!)

Overall Review: Sorry about the silly title. Just wanted something that would stand out from the pack. The Sabertooth is not as flashy as the ROG or Deluxe ASUS X99 boards. Nonetheless, it is a stable, solid MB. I'm not trying to make a flashy rig, just something solid, stable, and more dust-proof than average.

I have only ever used AUS MBs, so can't compare performance to other MB brands. Sorry.

The only weird thing I ran into is the following. I have an external Sans Digital 5-bay USB3/eSATA RAID drive enclosure. It works fine if I plug it into the USB 2.0 or USB 3.1 ports, but is not recognized at all if I plug it in the USB 3.0 ports. I tried different BIOS settings but had no luck. I have no idea why it's doing this, but I point it out in case anyone might run into a similar scenario.

I am using the Intel 750 NVME SSD as my boot drive and it works flawless with max read of 2700+ MB/sec. Freaking massive! At the time of purchase the ASUS HyperCard was not available so I went with the PCI slot version. Turned out to be a good decision because I have a Titan X and Tesla K20, which is similar to a dual GPU scenario, and I would have not been able to have the M.2 HyperCard adaptor and the K20 in place together. So, my only option was the PCI version of the NVME drive.

I should note that I am not using any of the internal SATA connections on this setup. I have the NVME for OS and programs, and several external drives going through the back USB 3 and 3.1 ports for data storage.

For overclocking, I got 4.3 GHz with 64 GB DDR4 RAM using the XMP1 setting and an Intel 5960X. I think the limits on the overclocking are part silicon lottery and part the fact I am using the full RAM capacity. I have noticed in the past that the more RAM, the harder to get higher overclocks.

The whole system runs relativity cool. 35oC at idle and 65-70oC when running hard core benchmarks. When using real world applications that max out all 8 cores, I am getting about 60oC. CPU cooler is a Corsair H110i. Build is in a Fractal Design R5 case.

Overall, I am very happy with the performance of the Sabertooth X99 MB. Obviously the MB is important as it sits as the center piece of the whole rig. Again, my goal was stability as much as performance, and was willing to sacrifice a couple hundred MHz on overclocking to have the extra stability, dust-proof-ness, etc.. I definitely recommend the product to someone looking for these kind of specs.

System:
Intel 5960X (4.3 GHz stable overclock)
Asus X99 Sabertooth Motherboard
64 GB Corsair Vengeance LPX DDR4 (2400) RAM
Intel 750 Series 1.2 TB NVME SSD (PCI version)
EVGA GeForce Titan X
NVIDIA Tesla K20
Asus Sonar Essence I sound card
EVGA Supernova 1000G2 power supply
Fractal Design R5 case
Corsair H110i CPU cooler
several external USB 3 hard drives for data storage

Pros: Loved the board. The overclocking on the CPU was phenomenal. Was perfect for my purposes. The overall build quality was great.

Cons: After 9 months of use, all 4 memory slots on one side of the board stopped working. Everything else works fine, I've tested each memory module in different slots, and in another motherboard. They're just not there any more.

Overall Review: I'm going to inquire with ASUS about an RMA. I think it should still be under warranty.