ASUS M4A89GTD Pro/USB3 890GX Motherboard
The 890GX Chipset
Let’s start off with a quick discussion about the new AMD 890GX chipset and its features. There are a few differences from the previous chipsets, so let’s take a look at the block diagram:
One of the notable differences here is the lack of support for DDR2 memory, as AMD appears to have finally made the full switch over to DDR3 with the 890GX. Based on the price of this product lineup, AMD is targeting the AM3 Athlon II processors, which we’ve seen to be extremely capable quad core chips, particularly for the budget range.
The block diagram also shows that the 890GX has a 16X PCI Express 2.0 that can be divided into two X8 lanes for a CrossFire X setup, a step up from the 785G we previously saw that only featured a 16/4 configuration. There are also six X1 lanes available for any other expansion cards from the 890GX. Additionally, however, another two X1 lanes are also available through the SB850 southbridge, bringing a wide range of options to users here.
Another significant difference with the 890GX is the integration of the SATA 6GB/s support with that SB850 southbridge. Solid States Drives that can take advantage of this are currently extremely lacking, but they are on the way as we’ve seen with Crucial’s RealSSD, as well as the upcoming Sandforce-based SSDs. We also see that USB 3.0 is available, and the controller interfaces though AMD’s 2GB/s A-link Express III from the 890GX "northbridge" (admittedly, a misnomer) to the SB850 southbridge by means of four 2.0 lanes.
Lastly, the SB850 supports 14 USB 2.0 ports, two more than the 785G or 790GX chipsets.