ASUS Sabertooth 990FX AM3+ Motherboard Review

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By now everyone reading this article should know that AMD is on the cusp of releasing their eagerly anticipated Bulldozer architecture. On the desktop side of things, Buldozer will be released as processors with the Zambezi designation. Naturally, these new 8-core CPUs and their derivatives will use the AM3+ socket so new motherboards will be released to support them. Enter the 990 series of chipsets, a slightly different spin on the outgoing 890 series. For the purposes of this article we will be concentrating upon the enthusiast-oriented 990FX chipset.

The differences between the 890FX and the new 990FX chipsets are much less significant than the name change would have you believe. Truth be told, the 990FX Northbridge is basically a carbon copy of its predecessor with a slight change in the microcode structure in order to support the unique needs of AM3+ CPUs. It is paired with a 950 Southbridge which is nothing more than a rebadged SB850 chip. Luckily, the SB850 was forward looking enough that changes weren’t necessary as it already supports SATA 6G. Combined, the “new” Northbridge / SouthBridge combination has more enough PCI-E 2.0 lanes to support any current third party USB 3.0 controller as well.

As with almost every past AMD isn’t about to let their clientele out in the cold so the 990FX is backwards compatible with current AM3+ CPUs. So you can buy in confidence without worrying about any upgrade paths closing a few months down the road.

It seems like this new chipset and the upcoming Bulldozer processors have sparked quite a bit of interest among certain industry circles. Some motherboard manufacturers like ASUS will be adding features to their 990FX boards which weren’t seen on previous generations. Things like UEFI support, SLI certification (with NVIDIA’s blessing) and dynamically expanded overclocking options were all MIA from the 890FX boards but will now be included alongside an AM3+ socket.

An expanded set of capabilities doesn’t necessarily mean that 990FX boards will begin edging up in price either. Take the subject of today’s review for example: the ASUS 990FX Sabertooth. It sports a laundry list of features alongside components which are durable enough that ASUS gives it a 5-year warranty. It’s price? $209 before rebates. If that isn’t tempting, we don’t know what is…

 

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The 990FX Under the Microscope

The 990FX Under the Microscope

AMD’s “new” range of 900-series motherboards spans the upper end of their market and will initially consist of the 990FX and 990X chipsets.

The “990FX” may indeed sound new but it is nothing more than an 890FX with updated microcode to support upcoming Zambezi processors while the 950 Southbridge is simply a rebranded SB850 chip. Is this a bad thing? Well, we don’t think so because the 890/850 combination used on previous boards proved to be forward thinking enough that many of its features (like SATA 6G and USB 3.0) are still in their infancy and have a long way to grow.

One of AMD’s most distinguishing features over the last few product generations has been their commitment to offering backwards compatibility for their motherboards and forwards compatibility on the processor end of things. Even though the 990FX series boards will feature support for upcoming AM3+ processors, the socket layout makes them compatible with all current AM3 processors as well. This will allow current and slightly older processors to be used on these boards. So while 990FX may not seem like an upgrade for 890FX users, it is a no-brainer purchase for people who want an AMD platform now but are worried about what’s coming down the pipeline.

While Intel has transferred most of their Southbridge functionality to their processor die, AMD has staunchly adhered to a two-part chipset configuration consisting of a Northbridge and a Southbridge. We have seen this layout persist through the 790FX days on to the 890FX and now once again on the 990FX. This may change in the future, for the time being all current AM3 processors and upcoming AM3+ products only feature on-chip DDR3 memory controllers while all the I/O and expansion slot functions are handled through the chipset. We also get native support for DDR3 1333Mhz memory while the processor and 990FX Northbridge communicate through a Hypertransport 3.1 link at 6.4 GT/s. Yes, that's an upgrade which will likely benefit processors.

The Northbridge of AMD’s two-chip solution acts as a controller hub for most of the board’s PCI-E 2.0 lanes and facilitates communication between the SB950 and the processor. The 32 dedicated graphics card lanes are split up into either two 16x slots or can be evenly dispersed for up to a quartet of 8x slots which gives the boards incredible flexibility for multi GPU setups.

After a long hiatus, SLI finally sees the light of day on an AMD chipset with support through NVIDIA’s driver stack. This is a huge step for both AMD and NVIDIA and it could open up some new markets for these motherboards.

Meanwhile, the remaining ten PCI-E 2.0 lanes are divided up into one grouping of four lanes while an additional six lanes 1x lanes can be dispersed as needed for integrated components like audio and networking controllers.

This layout tells us a thing or two about the Bulldozer-based Zambezi CPUs which are due out in the coming months. It seems like their baseline interface with supporting motherboards hasn’t changed much from the current generation of processors which means they’ll retain the on-die memory controller while supporting DDR3 speeds of 1333Mhz. This can be counted as a good thing for consumers and motherboard manufacturers alike since motherboards will likely stay relatively inexpensive compared to their Intel competitors.

Moving on down to the SB950, we see that AMD has once again foregone any updating as the layout is absolutely identical to that of the SB850. The chipset interconnect still uses a 2GB/s interface dubbed “Alink Express III” which essentially uses four PCI-E 2.0 lanes to speed up on-board communications.

Speaking of the Southbridge, we see that AMD has retained 6Gbps SATA support but still hasn’t progressed to native USB 3.0 support. Third party USB 3.0 controllers can be interfaced to the Southbridge or Northbridge chipsets using the 1x PCI-Express 2.0 lanes for a maximum theoretical throughput of 500MB/s.

 

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Package & Accessories

Package & Accessories

Now that we have gone over the Sabertooth 990FX's chipset and its extensive specifications, it is time to take a look at the packaging and the included accessories. This is a $209 mainstream-level motherboard, so we don't necessarily expect a standout accessories bundle.

Let's check it out:

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The Sabertooth 990FX ships in a package that has a different colour, but identical overall theme as the other ‘The Ultimate Force’ models like the Sabertooth X58 and Sabertooth P67, the latter of which we are currently in the process of reviewing. The box actually has a flap which details the numerous features which are exclusive to this particular motherboard and the TUF series in general. What obviously caught our trained eyes first were the new Socket AM3+ and AMD 900 Series chipset logos, since that’s what we have been looking forward to…despite the lack of any actual AM3+ processors.

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Once you open the box, you are greeted with the inner protective tray that holds the motherboard, while the lowers half holds the accessories, manuals, and so forth.

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The accessories bundle doesn’t really come with any surprises, but there's nothing missing either. There are four SATA 6Gb/s cables, a 2-way SLI bridge connector, an anti-EMI I/O panel, a ‘Certificate of Reliablity’ that details what tests the components on this TUF series motherboard can survive, and Q-Connectors, which make attaching the case cables to the system panel connector a much easier process.

 

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A Closer Look at the Sabertooth 990FX

A Closer Look at the Sabertooth 990FX

As we have come to expect from ASUS, this motherboard has a well though out layout. The 8-pin CPU power connector, 24-pin ATX power connector, eight SATA ports, USB 2.0 and FireWire headers are all ideally located on the edges of the motherboard. We do however wish that the front panel USB 3.0 header was located at the very bottom of the motherboard, instead of below the memory slots where effective cable routing/hiding can be little more difficult.

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This motherboard features a new 8+2 phase DIGI+ VRM digital power design, which is similar to the one we saw on the P8P67 PRO. Part of the DIGI+ VRM design are the Dual Intelligent Processors 2 (DIP2), consisting of the independent EPU (Energy Processing Unit) and TPU (TurboV Processing Unit) controllers. Thanks to the digital VRM and the TPU controller, this motherboard has extremely precise 0.005V voltage increments, five levels of Load-Line Calibration (LLC), very fast VRM phase switching with fine 10KHz switching frequency adjustments. The EPU controller monitors CPU loading and controls the number of active power phases, while also adjusting the voltages and multipliers on-the-fly in order to regulate power consumption. It is also connected to the chipset and memory VRMs, and optimizes their power efficiency as well. The main benefits of this new DIP2 design are that you can have full control over the system settings without using any CPU resources, and it’s no longer necessary to choose between power management (EPU) and overclocking (TPU).

From what we can tell right now, all of these new AM3+ motherboards will feature a black socket. It is a minor but effective way of differentiating AM3+ from the older AM2/AM2+/AM3 sockets. Those with eagle eyes will also notice that the AM3+ socket on this Sabertooth model features two small raised parts whose purpose is currently a mystery to us. We also believe that the pin holes look slightly wider, but don’t quote us on that.

Another distinctive change is the two-part heatsink mounting bracket, which differs from previous implementations, but also appears to be a ASUS-specific change instead of one mandated by AMD.

The two CPU fan headers are a terrific addition that we hope becomes a standard feature on all slightly higher-end motherboards.

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While the MOSFET heatsink is obviously a very robust looking piece, what really draws the eye is its unique texture. It is covered in CeraM!X, which is ceramic coating technology that ASUS only uses on The Ultimate Force (TUF) series motherboards.

This model only features one perfectly located 8-pin CPU connector, which is probably a good sign that AM3+ processors will not be power hogs, at least we are hoping.

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The Sabertooth 990FX has a pretty cool looking northbridge heatsink to our eyes. Part of this is obviously due to the CeraMIX coating that gives it a really gritty appearance. This heatsink doesn’t feature a particularly high fin density, but the way the fins are spaced ensures that they can really make use of any available airflow. The northbridge cooler is connected to the MOSFET heatsink via a flattened copper heat-pipe.

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The Sabertooth’s DDR3 memory slots officially support up to DDR3-1866, which is one of the benefits of the 990FX chipset, but ASUS have also validated this motherboard for overclocked operation up DDR3-2000. The 2-phase power design for the memory slots will have no issues handling the load. We are glad to see that ASUS are continuing the user-friendly Q-DIMM memory slot design, which is clip-less on one end. The reason for this innovative design is simply to make it easier to remove the memory modules.

In the top-right corner is the MemOk! button, which can be used to fix any memory compatibility issues in order allow the system to boot. As we come to expect, the 24-pin ATX power connector is right on the edge of the motherboard, exactly where it should be.

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This motherboard comes with a front-panel USB 3.0 header, and is one of the first to feature the new ASMedia ASM1042 USB 3.0 host controller, which as you will see later has much better performance than previous USB 3.0 implementations.

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The modern looking and low profile southbridge heatsink also features the unique ceramic-coating. It really doesn’t have much to cool, so form over function is not really a big deal in this case.

This motherboard features 8 right-angle SATA ports, 6 of which are supplied by the ‘new’ SB950 southbridge, which is identical to the previous SB850 southbridge. These six brown ports are all SATA III 6Gb/s and support RAID 0,1,5,10, JBOD, while the two black ports are SATA II 3Gb/s and come from a JMicron JMB362 controller.

 

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A Closer Look at the Sabertooth 990FX pt.2

A Closer Look at the Sabertooth 990FX pt.2

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Near the bottom-right corner, you can spot the front-panel header, overclocking-focused TPU (TurboV Processing Unit) controller, the socketed BIOS chip, and the clear CMOS jumper. There is also one of the two additional USB 2.0 headers, good for another four ports and possibility allowing up to 14 USB 2.0 devices to be connected to this motherboard.

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The Sabertooth 990FX has a good layout and nice assortment of expansions slots. There are four mechanical PCI-E x16 slots, one PCI-E x1 slot and one legacy PCI slot. Although this motherboard does feature four mechanical PCI-E x16 slots, the dark grey slot can only operate at up to x4 mode, and is thus unsuitable for graphics card use. As a result, this model is ‘limited’ to 3-way CrossFireX and 3-way SLI. SLI is obviously a key selling point here, and we can’t hide that fact that we are ecstatic that NVIDIA’s multi-GPU technology has once again found its way onto the AMD platform.

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The Realtek ALC892 is a good sounding eight-channel High Defition Audio codec. The VIA VT6308P is a IEEE1394/FireWire controller. The ASUS T.Probe IC is one of the power phase management controllers. These chips manage the VRM area in real-time to balance load across the power phases and ensure the best possible efficiency and temperatures. The JMicron JMB362 supplies the two eSATA ports on the rear I/O panel. The Realtek RTL8111E is a Gigabit LAN controller running off the PCI-Express bus. Last, but certainly not least is the new ASMedia ASM1042, a USB 3.0 host controller that offers much better performance than the widely-used NEC/Renesas D720200F1 chip that is found on most motherboards.

On the rear I/O panel, ASUS have placed a PS/2 keyboard/mouse combo port, ten USB 2.0 ports, optical S/PDIF connector, FireWire port, two eSATA ports (the green one is powered) , two USB 3.0 ports, a Gigabit LAN port, two USB 3.0 ports, and the six audio jacks.

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When we flipped the Sabertooth over, we were glad to that this motherboard’s cooling system is held in place by mounting springs, screws and washers. As you can see there is also a metal strip on the back of the board, which serves as a heatsink for the rear-mounting MOSFETs. This is a nice touch for a motherboard sold on its promise of superior reliability.

 

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Hardware Installation

Hardware Installation

In the Hardware Installation section we examine how major components fit on the motherboard, and whether there are any serious issues that may affect installation and general functionality. Specifically, we are interested in determining whether there is adequate clearance in all critical areas.

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The Sabertooth 990FX has a very low profile cooling system and a clutter-free CPU socket area, so there really shouldn’t be any issues when installing even the largest CPU cooler or even LN2 pot.

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Because of the way in which CPU coolers must be installed on AM3/AM3+ motherboards, the installation of memory modules with tall heatspreaders is a definite issue with the Sabertooth 990FX. As you can see, in this orientation the CPU cooler overhangs the first memory slot and even slightly overhangs the second slot. The end result was that we couldn’t install our Corsair Dominator GT modules on this motherboard and had to result to our reference height Crucial Ballistix Tracer kit. You will need to use memory modules with heatspreaders no taller than 4.25 centimeters if you plan to install your CPU cooler in this orientation and avoid any contact.

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Thanks to the expansion slot layout, there is a nice gap between the Q-DIMM memory clips and the back of the graphics card, so there are no issues when installing/removing memory modules. The 24-pin ATX power connector and the 8-pin CPU power connector are both ideally placed, so that makes assembling and disassembling the system just a tad easier.

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When you install two dual-slot graphics cards on this motherboard you will still have access to two PCI-E x16 slots (x8 & x4 electrical), but the legacy PCI slot will regrettably be covered. If you install a third dual-slot graphics card in the dark brown PCI-E x16 slot, you will obviously be restricting easy access to the CLR CMOS jumper and FireWire/USB/front-panel headers. There will also be some overhang, but that is to be expected on an ATX motherboard.

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There is nothing on the back of the motherboard that would give us cause for concern regarding clearance issues with an aftermarket CPU cooler mounting bracket.

 

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BIOS Rundown

BIOS Rundown

The Sabertooth 990FX obviously features the terrific new ASUS EFI BIOS, which is based on the new Unified Extensible Firmware Interface (UEFI) specification and replaces the ancient text-only BIOS layout that we have all grown accustomed to. Most noticeably, UEFI brings forth a graphical user interface (GUI) and the ability to use the mouse instead of just keyboard in the BIOS environment. However, this new BIOS spec also features other new capabilities as well, like support for boot drives above 2.2TB, which previously required third-party storage cards, and the potential for faster boot times.

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The EFI BIOS has two different interfaces: EZ Mode and Advanced Mode. Any self-respecting enthusiast will want to switch to Advanced Mode right away via the Exit menu in the top right corner, and then by selecting the appropriate Setup Mode in the Boot section.

By default, the EZ Mode screen provides a user-friendly visual overview of basic system information like bios version, CPU type, memory frequency, total memory, system temperatures, voltages, and fan speeds. It also allows you to select between three different system performance modes (Power Saving / Normal / ASUS Optimal), and very simply select boot drive priority with your mouse or keyboard. While it is intended for novice users, we would have liked to a few more capabilities added to EZ Mode, particularly the auto-overclocking OC Tuner feature since this is arguably where it would get the most use.

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The Ai Tweaker tab is where all the fun happens. Once the manual option is selected in the Ai Overclock Tuner setting, the BIOS opens up to reveal all of the essential system clock control options: individually adjustable Turbo multiplier(s) (ie: CPU multiplier), bus speed, memory frequency, CPU/NB frequency, HyperTransport Link frequency, etc. Users also have the option of enabling/disabling EPU power saving mode.

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When you enter the DRAM Timing Control sub-menu, you are presented with just about every memory timing that you could want. The DRAM Driving Control sub-menu amazing provides even further control over memory settings, but is definitely best left to professionals

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One of the benefits of the new DIGI+ VRM is that it can be significantly tweaked by users in order to maximize power efficiency for day-to-day operation or stability and performance while benchmarking or overclocking.
Naturally, all the important system voltages are present and accounted for, and can be manually entered at precise 0.005V increments.

 

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BIOS Rundown pt.2

BIOS Rundown pt.2

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The CPU Configuration section is where you can enable/disable the CPU-specific features like Cool ‘n’ Quiet, and C1E, and AMD’s SVM virtualization technology.

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The North Bridge section is where you can enable/disable IOMMU support, which you don't really need unless you're doing virtualization, and tweak a few memory controller options.

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The SATA Configuration section is where you can set SATA mode, as well as enable or disable hot plug functionality.

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The USB Configuration tab is obviously home to all the USB settings.

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If you have a chip with cores and/or cache that can be unlocked, the aptly named CPU Core On/Off Function is what you will need to use in order to unleash your processor’s full potential.

The Onboard Devices Configuration sub-menu is also where you can enable or disable the various onboard controllers like as well as all the onboard devices like audio, LAN, FireWire, eSATA, and USB 3.0.

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The Monitor tab has some fairly basic temperature and voltage readouts. Usually we would say that we would like to see additional readouts, but the voltages are listed in real-time in the Ai Tweaker section, and the 10 temperature sensors can all be monitored in the Thermal Radar utility.

ASUS have outfitted the Sabertooth with extensive fan control functionality, so if you want to get all your fans spinning just right, this section should be right up your alley.

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The Boot tab is essentially where you set storage device priority and select the boot drive, where you can set supervisor and user passwords, and also disable the full screen logo.

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ASUS EZ-Flash 2 is a built-in utility that greatly simplifies the BIOS updating process. You can easily update your BIOS from a ROM file located on your hard drive(s), USB flash drive(s), or even a CD. It's quick, painless, and it takes the worry out of BIOS flashing.

The ASUS O.C Profile feature gives users the option to save and switch between BIOS profiles, for example an everyday profile and a benchmarking profile. Not only is this infinitely quicker than manually inserting every setting, but the profiles can be saved and shared among other Sabertooth owners.

 

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Included Software

Included Software

For this brand new platform, ASUS have combined their numerous software utilities into the much more user-friendly Ai Suite II toolbar. As you’ll see this new approach is much more organized than having various apps scattered around everywhere.

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After going through the brief installation process, you will be greeted with this handy new Ai Suite II toolbar, which gives you one-click access to an unprecedented level of control over most system settings.

First and foremost, this Ai Suite II implementationfeatures the Thermal Radar utility. One of the advantages of the Sabertooth motherboard series is improved monitoring capabilities, and this application allows users to keep an eye on this motherboard’s numerous temperature sensors, voltage readouts, and fan speeds.

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The TurboV EVO tab in AI Suite II allows users to tweak the CPU bus, CPU voltage, CPU/NB voltage, and DRAM Bus voltage in Windows and in real-time without exiting and rebooting the OS. Additional voltages for the HyperTransport Link , northbridge, southbridge, etc. are also available by clicking the Advanced mode. The CPU multiplier(s) are also fully and individually adjustable within this utility.

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ASUS DIGI+ VRM allows users to adjust VRM voltage and frequency modulation to enhance reliability and stability. It also provides power efficiency, generating less heat to provide longer component lifespan and minimize power loss.

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Sensor Recorder, as its name suggests, allows users to monitor and record changes in system voltages, temperatures, and fan speed.

Ai Charger+ allows users to supercharge their USB ports, and enable up to 3 times faster charging of mobile devices.

The Monitor tab features the Sensor and CPU readouts that are found in the TurboV EVO and Sensor Recorder utilities.

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Why bother visiting the often slow ASUS.com website when you can simply update your BIOS from within Ai Suite II.

This little app allows users to change the full screen boot logo to whatever their heart desires.

System Information displays basic... system information, just the same stuff you can see in CPU-Z.

Settings allows users to customize various aspects of the toolbar, as well as completely tweak the aesthetics of the various utilities.

 

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Test Setups & Methodology

Test Setups & Methodology

For this review, we have prepared two different test setups, representing all the popular platforms at the moment, as well as most of the best-selling processors. Motherboards aside, the two test setups feature identical components, memory timings, drivers, etc. Aside from manually selecting memory frequencies and timings, every option in the BIOS was at its default setting.

AMD Phenom II AM3 Test Setup​

For all of the benchmarks, appropriate lengths are taken to ensure an equal comparison through methodical setup, installation, and testing. The following outlines our testing methodology:

A) Windows is installed using a full format.

B) Chipset drivers and accessory hardware drivers (audio, network, GPU) are installed followed by a defragment and a reboot.

C)To ensure consistent results, a few tweaks were applied to Windows 7 and the NVIDIA control panel:

• UAC – Disabled
• System Protection/Restore – Disabled
• Problem & Error Reporting – Disabled
• Remote Desktop/Assistance - Disabled
• Windows Security Center Alerts – Disabled
• Windows Defender – Disabled
• Windows Superfetch – Disabled
• Screensaver – Disabled
• Power Plan - High Performance
• NVIDIA PhysX – Disabled
• V-Sync – Off

D) Programs and games are then installed & updated followed by another defragment.

E) Windows updates are then completed installing all available updates followed by a defragment.

F) Benchmarks are each ran three times after a clean reboot for every iteration of the benchmark unless otherwise stated, the results are then averaged. If they were any clearly anomalous results, the 3-loop run was repeated. If they remained, we will mention it in the indvidual benchmark write-up.

Here is a full list of the applications that we utilized in our benchmarking suite:

• ATTO Disk Benchmark v2.46
• CrystalDiskMark 3.0.1 x64
• HD Tach 3.0.4
• HD Tune Pro v.460
• AIDA64 Extreme Edition v1.70.1419 Beta
• ScienceMark 2.0 32-bit
• MaxxMEM2 Preview
• wPrime Benchmark v2.03
• HyperPI 0.99b
• PCMark 7 Professional Edition 64-bit v1.0.4
• Cinebench R10 64-bit
• Cinebench R11.5.2.9 64-bit
• WinRAR 3.93 x64
• Photoshop CS4 64-bit
• Lame Front-End 1.0
• X264 Benchmark HD (2nd pass)
• 7-Zip 9.20 x64
• POV-Ray v3.7 RC3
• Deep Fritz 12
• 3DMark06 v1.2.0
• 3DMark Vantage v1.1.0
• 3DMark 11 v1.0.1.0
• Crysis v1.21
• Far Cry 2 1.02
• Left 4 Dead
• Team Fortress 2
• Valve Particle Simulation Benchmark
• Word in Conflict v1.0.0.0
• Resident Evil 5 1.0.0.129
• X3: Terran Conflict 1.2.0.0

That is about all you need to know methodology wise, so let's get to the good stuff!