ASUS Sabertooth 990FX R2.0 Review

ASUS Sabertooth 990FX R2.0 Closer Look:

The ASUS Sabertooth 990FX R2.0 is a standard ATX form factor board at 12" x 9.6" and, as I eluded to on page one, is loaded with features and tech to go with the high military grade components outlined on the Certificate of Reliability you receive with the accessory bundle. You might not think of the board I have thus far described as understated, but the Sabertooth is actually very tastefully schemed and colored.

The Sabertooth is outfitted with four full length PCIe 16x slots and a single PCIe 1x slot in between the first and second PCIe 16x. A single legacy PCI slot is found near the bottom as well for those older audio cards cards you just can't bare to part with. The PCB is a true black multi-layered with tracers only visible only by texture and not the copper coloring. The Sabertooth seems to have an inordinate amount of large white font spelling out the model and all of the major systems and features as well as a large white T.U.F. symbol between the first and second full length PCIe slots. The board itself is populated with high quality shock tested, moisture resistant capacitors, MOSFETs, and inductors that have a swipe of the camo-themed colors of the rest of the board.

The back of the board reveals only the heavy backplate for the mounting of cooling solutions, a very heavy gauge metal bracket for the spring loaded screw downs for the VRM heatsink, and about 4,000 solder points.

 

 

 

 

 

 

 

 

 

 

 

 

Around the back of the Sabertooth we have a very well connected I/O panel. In total the connectivity you are looking at is: one PS/2 keyboard/mouse combo port, two eSATA 6Gb/s ports, one Ethernet port, four USB 3.0 ports, eight USB 2.0 ports, one Optical S/PDIF out, six audio jacks, and one USB BIOS Flashback Button. The Sabertooth's connectivity keeps pace with boards that are in the north of $200 range.

 

 

The connections for discrete graphic options are plentiful with the Sabertooth R2.0. Four PCIe 2.0 16x slots (three being double slotted) facilitates three card Crossfire and SLI. When occupying two PCIe slots, the configuration is at 16x/16x electrically. When using three of the slots the configuration runs at 16x/8x/8x.The second black full length PCIe slot is 16x mechanically and runs at 4x electrically. In between the first and second full length PCIe slots is a single PCIe 2.0 1x slot for sound cards, capture cards, or other devices.

The full length 16x slots use a securing mechanism ASUS calls Q Slot; a fishtailed-style locking mechanism that flips forward to a 45 degree angle when fully locked in and is pushed flat towards the PCB to release the device. A single legacy PCI slot can still be found on the Sabertooth. I look for these to disappear completely in the near future along with the CD/DVD player.

 

 

Along the bottom of the PCB we come to the majority of the front panel connectivity. Having a look from left to right we have a 4-pin SPDIF_out. Below this is the 10-1 pin AAFP connector. To the right marked 'TB_Header' but not called out in the board connection scheme listing is a Thunderbolt header. Next is the 20-1 TPM header. The LED next to it is a green standby power LED. Moving to the right is the first of a pair of 10-1 pin USB 2.0 connections (the second is on the adjacent image). They are USB 1314 and USB 1112, respectively. Next to the right is the Clear RTC RAM 3-pin jumper marked (CLRTC). This jumper allows you to clear the real time (RTC) RAM of all system information (date, time, etc) as well as all system parameters that are controlled and kept 'live' by the on-board CMOS battery.

Up next is the Serial port connector 10-1 pin (Com 1). The DirectKey button just adjacent to the right lets you instantly gain access to the BIOS for quick changes or overclock profiles. To the right of this sits the 20-pin system panel connector. Just above and to the left of the front panel connections is the direct connector (2-pin DRCT); with this connection you substitute your front panel reset button as the DirectKey function. In other words with this connected the reset button will take you directly to the BIOS for any changes that may have caused a crash and make changes before saving and exiting. This option lets you access the otherwise onboard DirectKey button from the front panel and not have to enter the chassis to activate.

 

 

Just above the row of front panel connectivity we just covered is the single socketed BIOS. That's right, there is only a single BIOS chip there, however on the rear I/O panel is the BIOS Flashback feature that is capable of flashing a damaged BIOS back in shape. The BIOS Flashback feature can be used to update or recover a damaged BIOS. Using only standby power, you can update or re-flash your BIOS, or try out a new BIOS with a Flash drive containing the BIOS version you wish to update to. Upon inserting the Flash memory you just press the BIOS Flashback button on the rear I/O panel and hold it for three seconds.

The BIOS will be automatically updated and an LED on the Sabertooth will flash green when successfully flashed. BIOS Flashback can even update the BIOS without a CPU or memory installed, and be activated to check for and update to the latest BIOS automatically. This is a hardware-based solution and you can see the BIOS support chip directly above the socketed BIOS just above the PCIe slot in the image below.

 

 

Moving to the lower right side of the PCB we find the eight SATA 6Gb/s ports to go with the two eSATA ports on the rear I/O panel. Six of these (brown) are AMD SB950 controlled and support RAID function 0,1,5, and 10, while two of the SATA 6Gb/s (white) are controlled by ASMedia ASM1061 controller. The layout of the SATA ports is very good and causes no interference when three of the longest graphic cards are installed.

 

 

Higher up from the SATA 6Gb/s ports are the quad DIMM slots of the Sabertooth R2.0. The dual channel architecture supports 32GB of DDR3 1866/1600/1333/1066 MHz ECC, Non-ECC, Un-buffered Memory. The DIMMs use what ASUS calls Q-DIMM. In essence this is an operating lock down on only one end of the DIMM. This makes for an easier installation with a better positive lock on the memory modules. On the outside edge of the DIMMs are the dual inductors for the Sabertooth R2.0 dedicated two phases of power delivery for the system memory. The update of the Sabertooth also includes the architectural implement of DDR3 'T-Topology' design. This feature does not show up in the manual or on the Sabertooths product page, but I suspected it was incorporated given the accompanying features and did a bit of digging. Lo and behold it is. This means that ASUS has made the DIMM tracer distance the same for all four DIMMs.

To illustrate this I took a memory tracer snapshot from an older ASUS motherboard that is a lighter color so the tracers can be seen more readily. What the T-Topology system does is at a hardware level makes the distance traveled from both channels of the dual channel memory to the CPU the same distance, reducing or eliminating data synchronization and latency issues. In other words you don't have some signals or data waiting on the data from the channels that are farther away from the CPU. The old method of memory layout is called daisy chain. T-Topology arranges the routing of the tracers to a parallel system to facilitate data that is being read or written together to arrive together at the CPU or memory modules.

This helps with latency issues and aids in more stable overclocks. ASUS claims an average of 15% additional overclock headroom for the system memory. In turn higher and more stable memory overclocks means higher overall overclocks. Also new in the R2.0 is native support for 1866MHz memory. The 990FX chipset supports HyperTransport 3.0 and a transfer rate of up tp 5.2 MT/s. On the outside of the four DIMMs are the 20-pin USB 3.0 connector and the larger camo-beige connector of the 24-pin main ATX power.

 

 

 

At the heart of the ASUS Sabertooth 990FX R2.0 is the AM3+ socket that supports AMD processors up to 140W rating. The pin outs on the 990/950 chipset boards have been increased from .047 to .053 inch, with the 990 chipset ostensibly to provide better compatibility with pre-FX CPUs and better contact. Presumably those considering a board of this caliber and price range will be purchasing an FX processor or carrying over a previous flagship CPU and the likes of the Phenom II 970, 1100T, and the Bulldozer FX models are all compatible with the Sabertooth 990FX R2.0. The standard lever and tension plate is employed here, along with black standard AM3+ mounting brackets for various CPU cooling solutions that make use of it.

 

 

And now a look at how all of this powered and how it gets form your PSU to your CPU. The ASUS Sabertooth 990FX R2.0 is an 8+2 phase digital power design. Remember that the components used in the power array (the MOSFETs, capacitors, and chokes/Inductors) are all of military grade specifically spelled out by testing standards on the accompanying certification. I will be looking to see how these components and the efficiencies of the updated technology, such as E.S.P., will handle the added voltage and heat of a hopefully extreme overclock. In theory all of this should add up to higher overclockability and performance with less voltage pushed through the system. 

The power is controlled by multiple digital voltage controllers for both the CPU and DRAM, the 'Dual Intelligent Processors.' For the CPU and the DRAM they work by changing the switching frequencies as the VRM, CPU, and DRAM tuning occurs. Also implemented with the digital power delivery is VRM EMI reduction. This reduces electromagnetic interference to surrounding components. The result is much more precise voltage to the components as the power delivery profile changes and the overclocking changes are made. ASUS gives you complete control of this aspect in the BIOS where you can choose between 10% to 30% more capacitance to the memory, CPU, CPU/NB, and DRAM.

 

 

 

A power feature that ASUS states is exclusive to the Sabertooth T.U.F. series is E.S.P. (Efficient Switching Power) Design. I frankly can't see this remaining exclusive for very long if it produces the claimed results. There is not a lot of technical information available about E.S.P included with the Sabertooth so bear with me. Basically with the faster and more efficient phase switching the digital control brings with it, E.S.P. works by (or as a result of the ability to perform faster power switching) requiring less electrical input on the front end pre-filtering to deliver the needed voltage on the back end.

In short, if a component requires 6W of energy, the increased and more efficient switching frequencies with the increased efficiencies of the 'filtering' components needs only 6.6W of input to produce those six watts. Comparatively, previous or standard technology required 10W of input to produce the 6W the component needed. Obviously this is increased efficiency and reduced heat as well as longer component life and lesser cooling solutions, if I might extrapolate on those last two points. As power supply efficiency has reached 90%+ with capacitor and choke/inductor efficiencies, I am surmising that the MOSFETs are where the majority of efficiency advancements have been made with the E.S.P. system. This is a technology I will be following with great interest to see how efficient this can be made because one of the more interesting aspects of this tech is that it works for not only the CPU and DRAM, but also the graphics, USB 3.0, and LAN systems.

 

 

Topping off all of the heat producing components are the hefty and specially designed heat sinks on the Sabertooth 990FX R2.0. While being large finned and of varying asymmetrical shapes, the heat sinks on the Sabertooth are also covered with an innovation ASUS calls CeraM!X. CeraM!X, according to ASUS, is an aerospace innovation that conducts heat away from the heated surface faster as well as being rough in texture, creating even more surface dissipation areas (up to 50%). The CeraM!X coating can be found on the VRM and heatpipe-connected Northbridge, as well as the Southbridge heat sinks.The heat sinks of the Sabertooth are also held in place by hefty spring loaded screws. The heavier VRM/Northbridge is secured to a heavy gauge metal bracket on the back of the motherboard. This is a feature I for one appreciate as it eliminates the chance of the heat sink being bumped and tilted to the side, breaking the bond with the thermal tape or compound as well as keeping the PCB from warping from all of those heat-up and cooldown cycles.

 

 

 

The Southbridge heat sink, while being covered with the same CeraM!X material, has a large aluminum placard with the ASUS logo/insignia. In the right image you can see the screw and spring mounting system for the heat sinks. The red arrow apparently denotes the "TUF ENGINE!" Power Design.

 

Up in the right hand corner of the Sabertooth R2.0 are a couple of important and impressive features. Highlighted in red in the second image is the second of two digital controllers for the DRAM system memory. This in tandem with the new T-Topology not only allows for more precise voltage control, but affords higher overclocks at lower voltage and is good news for those of us that like to or need large amounts of system memory. This makes large amounts of memory and fast memory/CPU frequency no longer a 'pick one' proposition. Below the digital voltage control chip are the +2 phases of the 8+2 power phase scheme.

Just above and to the right of the digital voltage controller is one of the most impressive features I have found on a motherboard to date in the form of the MemOK button. In the case of faulty or unstable RAM settings, a press of the MemOK button will use a set of checks and algorithms to find a bootable configuration and allow you to boot up and change memory settings if needed. Also along the top edge are three of the six 4-pin fan headers and the 8-pin ATX12v power connection.

 

 

Rounding out the trip around the perimeter of the Sabertooth R2.0 takes us to the audio area of the board and the Realtek ALC892 8-Channel High Definition Audio CODEC. The Sabertooth's audio supports jack detection, Multi-Streaming, and the retasking of the front panel jacks through the Realtek software. The onboard audio features include Absolute Pitch 192kHz/24-bit True BD Lossless Sound as well as ASUS Noise Filter and Blu-ray audio content protection.

 

The second revision of the Sabertooth brings with it many innovative and exclusive technologies that are designed to produce higher performance and at the same time efficiencies in energy savings and reduction of heat. Next we'll have a look at the software side of things and the options you have at your disposal to put it to use. After that it will be back to the hardware side as we lock in the AMD eight-core flagship FX-8350 and see how far we can take it.