AMD AM3+ Chipsets

Launched during Computex 2011, AMD 9-Series chipset options offer functionality via three different northbridge solutions from AMD. All three have several new features specific to the 9-Series chipsets, but the majority of technology is carried over from AMD’s previous 8-Series products. The 9-Series from AMD is an incremental upgrade featuring Hypertransport 3.0 and native SATA 6Gb/s via the SB950. The big marquee difference is, of course, its new AM3+ CPU support. AM3+ CPUs have been part of the retail space for some time now, and the new AMD FX CPUs are their most recent addition. All 9-series chipsets provide DDR3-1866 memory support natively if a supporting CPU is installed. Also available is an IOMMU connection, which gives virtual machines direct access to hardware capabilities instead of offering a software interface using hardware emulation. This feature is aimed at Linux users and is not natively supported in the Windows environment.


The AMD 9-series is actually made up of several different products and each is tailored around a specific use. The desktop platform features three main products: the AMD 970, AMD 990X, and AMD 990FX. The above diagram shows a functionality diagram for the AMD 990FX, which is the chipset I'll be using to complete this review. The functionality that the others offer is not much different, but there are a couple differences amongst them.


The AMD 970 chipset offers a single PCIe 2.0 x16 connection for a single graphics card, while the 990X allows that link to be split into two separate PCIe 2.0 x8 connections for multi-card configurations. The 990FX chipset features two full PCIe 2.0 x16 connections for graphics, and has the option to, something that depends on OEM board layout and design, split each x16 PCIe 2.0 link into two separate PCIe 2.0 x8 links. That means that the 990FX can support up to four GPUs in CrossfireX. An extra x4 link is also available for add-on device support with, for example, a RAID card, while the AMD SB950 Southbridge chipset houses most of the basic I/O functionality, such as the six native SATA 6 Gb/s ports.

There are many board products on the market already that will support a shiny, new AMD FX-8350 CPU, but many will require a BIOS update before truly being compatible. Be sure to check. Make sure your board does have a proper BIOS before installing your CPU since things may not operate as they should without one. My first series of test sessions were with a board that was not truly ready for Piledriver, and the results were a bit underwhelming. Overclocking would not work at all without an up-to-date board. However, I had no problems at all once a proper BIOS was provided.