AMD 990FX Mobo Round-Up: Asus, ASRock, Gigabyte

Introduction and the 990FX Chipset

In preparation for the impending arrival of its Bulldozer-based FX-series of processors, AMD recently released their 9-Series chipsets. The AMD 9-Series currently consists of three products, the 970, the 990X, and the flagship 990FX chipsets.

At their core, all of the current AMD 9-Series chipsets are similar, and offer support for socket AM3 and AM3+ processors, DDR3 memory, PCIe 2.0 (with a varying number of lanes), and SATA III (6Gb/s). The chipsets differ in their support for AMD CrossFireX technology, however, due to a different number of PCI Express lanes available on each. The flagship 990FX supports up to four graphics cards, the 990X two cards, and the 970 only a single card. We should point out that some motherboards based on the AMD 990FX chipset will get official support for NVIDIA’s SLI technology as well, so those enthusiasts chomping at the bit for an 8-Core Bulldozer chip can enjoy some multi-GPU action with their graphics vendor of choice.

With AMD’s FX-Series process due to arrive sometime in the not too distant future, we thought it was a good time to check out a few high-end 990FX-based motherboards. We want to give you prospective AMD buyers a glimpse at some ‘boards designed with the FX-Series in mind. With that said, the 990FX chipset technically isn’t new. Take a look at the features and specifications ganked from AMD’s page below and then we’ll explain what we mean under the block diagram further down the page...

The ASUS CrossHair V Formula, ASRock Fatal1ty 990FX Professional, and Gigabyte 990FXA-UD7 we'll be looking at here all offer official support for upcoming 8-Core AMD FX-Series processors

AMD 990FX / SB950 9-Series Chipset
Specifications & Features
  • Ready to take AMD FX processors beyond all expectation Full socket compatibility for AM3+ and AM3 processors with Hypertransport 3.0 interconnects means you can upgrade your components when you’re ready to, and help ensure you get the most performance.
  • Support for up to 4 AMD Radeon HD Graphics boards with AMD CrossFireX technology PCI Express 2.0 technologies enable 2x16 or 4x8 configurations to enable higher levels of performance on your graphics applications. The AMD 990FX enables our best scalable platform for game-dominating performance with support for 2, 3, or 4 graphics cards.
  • Get ready to take control of your PC with the next generation AMD OverDrive software for full FX control. Customize your PC by getting full control of your different AMD components.
  • Take advantage of advanced technology like SATA 6Gb/s to help accelerate your connectivity. Enjoy the latest in performance benefits on your multiple RAID configuration support and enhanced SSD configurations with motherboards built around AMD 990FX.
Graphics Not Included, Up to 4 slots for Graphics Upgrade 
CPU Compatibility AMD Athlon, AMD Athlon II, AMD Phenom, AMD Phenom II, AMD FX
Memory Support AM3 and AM3+ socket motherboards support DDR3
PCI Express PCI Express 2.0
USB Up to 14 USB 2.0
SATA Supports SATA 6Gb/s devices

AMD 990FX / SB950 Chipset Diagram

Although the 9-Series chipsets, including the 990FX we’re featuring here, offer official support for upcoming Socket AM3+ based FX-Series processors, the chipsets themselves are not new. In fact, the 990FX chip and its companion SB950 Southbridge are identical to the 890FX and SB850. Socket AM3+ motherboards, like the ones we’re going to show you here, are outfitted with a newer 942-pin socket that’s backward compatible with socket AM3 processors. These boards will also offer full support for the frequency and power scaling technologies coming with Bulldozer. In effort to minimize the confusion that could stem from using 8-Series branded chipsets on motherboards with official support for Bulldozer, AMD thought it best to rename the chipset. AM3+ motherboards that will exploit all of the features of and officially support Bulldozer, will employ 9-Series chipsets.

Now, let’s get to some specifics. As you can see, the 990FX chipset supports AMD socket AM3 / AM3+ processors with DDR3 memory (including Athlon II, Phenom II and FX processors), and features a total of 42 PCI Express lanes, with flexible configuration options.

Other features of the 990FX chipset are HyperTransport 3.1, which is a 6.4GT/s link between the CPU and 990FX--an upgrade from the HT 3.0, 5.2GT/s link of the 890FX enabled by the new socket configuration. The chipset also features an A-link Express III interface with 4GB/s of bandwidth between the 990FX and SB950. The SB950 features almost all of the typical amenities of a modern chipset: USB 2.0, HD Audio, Gigabit Ethernet, PATA, and PCI are present. In addition, the SB950 also features an additional pair of PCI Express Gen 2 x1 lanes, along with native support of 6Gbps SATA. No native USB 3.0 support is present, however.

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