ASUS M5A97, M5A99X, and Crosshair V Motherboard Review Roundup
900 Series: Bulldozer Ready
The rumor on the street is that Asus makes a few motherboards. They may or may not be the world’s leading motherboard manufacturer. Asus may also have a pretty good reputation for quality and innovation in their products. It is tongue in cheek hour at PC Perspective. All joking aside, Asus anymore is the gold standard for quality manufacturing and design in motherboards.
Some months ago AMD released their AM3+ capable chipsets, though the release was not nearly as exciting as we had hoped. The AMD 900 series of chipsets are essentially the same silicon as those that power the non-integrated AMD 800 series. There are three SKUs that are currently available for the 900 series that Asus makes motherboards around.
The 990FX is the top product and it features 42 PCI-E 2.0 lanes. This allows it to support 2 x 16X PEG slots, and upwards of 4 x 8X slots (with a few lanes left over for use in connecting to the southbridge component). The big news here is that NVIDIA has finally relented and allowed AMD’s motherboard partners to license SLI support using these AMD chipsets. Otherwise, this chip is identical to the 890FX of yesteryear. It again features the IOMMU functionality for VM support.
The 990X is a cut down version of the 990FX in that it only has 22 PCI-E lanes. It does allow the use of a single 16X PEG slot, or can be divided into 2 x 8X PCI-E connections. This then allows the use of 4 x PCI-E lanes to connect to the southbridge. This chip supports Crossfire and SLI, though the stipulation for SLI is that the motherboard manufacturer must have a current SLI license from NVIDIA and has supported that technology in the past (such as the Intel X58 and P67 chipsets). This chip includes the IOMMU functionality as well.
Finally we have the 970, which sits at the low end. This is put forward as the budget member and does not natively support Crossfire and SLI. It has the full 22 PCI-E lanes, but cuts down on the number of concurrent connections. So it supports at max 1 x 16X PEG, with the southbridge handling any other PCI-E connections. This chip also shares the IOMMU functionality, so it could be of interest for those wishing to create an inexpensive VM server with actual hardware support.
All of these chips interface with the SB950 southbridge. This is again the same chip as the previous SB850. It features 14 USB 2.0 ports and a full six SATA 6G ports. It has eight PCI-E 2.0 lanes altogether, though four of which are relegated to the A-Link Express III connection. Even though we do not hear much about it, this chip does in fact feature a built-in 1 Gig-E MAC. Most of the time though we will see a Realtek or Marvell PCI-E 1X based controller on the vast majority of boards.
The primary reason for the number change on these chipsets is that it helps to differentiate boards that are primarily designed for use with Bulldozer CPUs. AMD has changed the power specifications slightly for Bulldozer, and while previous 800 series boards can support these new CPUs, they will not do so as efficiently and effectively as the new boards. The Hypertransport specification has been increased for these boards to 3.1, which allows a maximum speed of 3200 MTPS over the previous max of 2600 MTPS of the HT 3.0 specification.
Asus currently has a handful of motherboards out supporting the 900 series of chipsets. I have previously reviewed the 990FX SABERTOOTH, and that was a simply fantastic product considering the price and featureset. The other three have been making a visit to my test bench over the past few weeks. Ready for a hint? I liked them all.