|Biostar TA890GXB-HD mATX AMD Motherboard|
|Reviews - Featured Reviews: Motherboards|
|Written by Hank Tolman|
|Monday, 31 May 2010|
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AMD 890GX Chipset and SB850
The last chipset AMD released was the 785G Chipset in August 2009. Although that chipset was "new", it didn't really come with any new features. It was an improvement on the 780G chipset, and fell between that and the 790GX chipset. So in reality, the last new chipset released by AMD was the 790GX all the way back in August 2008. Since even before then, the flagship chipset for AMD has been the 790FX. With the release of the 890GX chipset, that all changes.
Somewhat upsettingly, the 890GX chipset doesn't bring a lot of new changes to the AMD chipset. The northbridge is almost identical to the 790GX chipset, though there are some differences. The main new features and additions to the AMD chipset that are released with the 890GX are actually found in the southbridge. The SB850 is new makeover of the older SB750 and adds, among other things, functionality for SATA 6Gb/s 6Gb/s, becoming the first core logic chipset to support natively integrated SATA 6Gb/s 6Gb/s.
The 890GX does bring some new features to the table, however. First off, the 890GX is limited to socket AM3 only. Both the 785G and the 790GX could be used in both AM2+ and AM3 motherboards, giving support to older DDR2 memory if desired. The 890GX, it seems, will be limited to only AM3 processors and DDR3 memory. The 890GX also touts support for the new 6-Core Thuban die processors. The chipset still uses the same 55nm process and utilized the same graphics as the 785G chipset. Additionally, the 890GX chipset mirrors the 790GX in that it offers 22 PCIe 2.0 in the northbridge and a full HT 3.0 5.2 GT/s link between the CPU and the northbridge.
The Radeon HD 4290 is nearly identical to the Radeon HD 4200 found in the 785G chipsets and is built on a RV6xx graphics core, which is nothing new for AMD integrated graphics. The only real difference between the 4290 and the 4200 is that the former runs a little faster on the core clock; 700MHz rather than 500MHz. We still have the 55nm node and around 205 million transistors and there are still 40 stream processors implemented. The graphics include all the same upgrades in video playback capability that arrived with the 785G chipset and the Radeon HD 4200. These include HDMI 1.3 standards, UVD2 / AVIVO support, DirectX 10.1, and full hardware MPEG-2/VC-1/H.264 video decode acceleration. Just like the chipsets, the 890GX offers the ability to pair another video card with the Radeon HD 4290 in Hybrid CrossfireX mode. Previously, the Hybrid CrossfireX was limited to only as high as a Radeon HD 34xx card, providing only very limited improvements to the IGP. Supposedly, the 890GX chipset, with the Radeon HD 4290 supports Hybrid CrossfireX with video cards up to the Radeon HD 5450. If this is true, it will provide a much better graphical advantage than ever before when utilizing CrossfireX mode with an IGP.
The audio on the chipset has also stayed the same on the new 890GX chipset. It offers 2 channel LPCM, or you can opt for 5.1 Channel Dolby Digital over HDMI. As I mentioned above, the bulk of the changes that come along with the 890GX chipset are actually found in the SB850 southbridge. The SB850 extends the amount of PCI Express 2.0 lanes by 2, for a total of 24 PCI Express 2.0 lanes. It adds support for an additional 2 USB ports, bringing the total to 14 ports. And, of course, it adds support for SATA 6Gb/s 6Gb/s, converting all 6 ports to the new standard. While this will undoubtedly prove extremely helpful in the future, it doesn't do a whole lot for the average user just yet. There are still only a handful of drives available, but they are rapidly becoming more and more popular. In order to avoid bottlenecks for the new SATA 6Gb/s standard and the possibility of USB 3.0 as well, AMD has increased the bandwidth on the Alink Express between the northbridge and the southbridge to 2GB/s in each direction over the previous 1GB/s in each direction. This really blows the latest Intel chipsets out of the water. So far no Intel chipsets support a native SATA 6Gb/s controller, but they also only allow the use of a controller on a PCIe 1.0 lane, limiting the bandwidth for USB 3.0 or SATA 6Gb/s to 250MB/s. If you get sneaky and bridge two PCIe 1.0 lanes, you can double the bandwidth, but it is an extra inconvenience for motherboard manufacturers.