AMD unveils 890GX chipset

CPU underdog AMD might be lagging behind its arch nemesis when it comes to CPUs with integrated graphics, but it’s at least taking advantage of its ATI IP when it comes to chipsets. The latest ATI IGP can be found in the AMD 890GX chipset, which has been launched today.

A Radeon HD 4290 handles the graphics duties, although you shouldn’t be fooled by the ‘4’ at the beginning of the model number. There’s very little to distinguish the 4290 from the Radeon HD 3300 found in the old 790GX chipset.

Both GPUs have 40 stream processors, and both are clocked at 700MHz. The main difference when it comes to 3D, as far as we can see, is that the 4290 supports DirectX 10.1, much like the Radeon HD 4200 IGP found in the 785G chipset, while the 3300 only supported the vanilla flavour of DirectX 10. That’ll be really useful for, erm, moving on...

On the plus side, the graphics chip supports DVD upscaling from 480p to 720p, as well as picture-in-picture display for Blu-Ray 1.1. It also supports AMD’s AVIVO HD technology, which includes hardware-accelerated 1080p video playback. The chip can also accelerate Flash video.

There’s not much else to shout about in the Northbridge itself, although AMD has made some notable tweaks to the new SB850 Southbridge, which replaces the SB750. The new chip fully supports up to six 6Gb/sec SATA 3 connectors for the latest hard drives, and it also supports up to 14 USB 2 ports, whereas the SB750 only supports 12.

Where’s the USB 3 support? Don’t worry, it’s there, but it’s just not in the chipset itself yet. Instead, AMD has teamed up with NEC to offer a third-party USB 3 controller with the chipset to its motherboard partners. AMD is also particularly chuffed about this implementation, as the controller is connected to the chipset via a PCI-E 2.0 interface, providing a chunky 500MB/sec of bandwidth, which AMD says is double what you get from a controller hooked up to Intel’s H55 or H57 chipsets.

Similarly, AMD also has a super-fast Alink Express III 2GB/sec link between the Northbridge and Southbridge, ensuring that there’s plenty of bandwidth for all the to-ing and fro-ing of data that could be going on when you have six SATA 3 drives hooked up.

AMD’s product marketing manager Adam Kozak explained that “with those other [Intel] chipsets, unless an expensive bridge chip is used on the motherboards, when they hook up the PCI-E lanes to either a USB 3 or a SATA 3 controller, you’ve actually got access to half the bandwidth [250MB/sec]."

In terms of other specs, it looks as though 890GX motherboards will only support AM3 CPUs, so you can connect DDR3 memory up to speeds of 1,333MHz (PC3-10666). Comparatively, the old 790GX chipset could be used with both AM3 and AM2+ sockets, giving you a choice of both DDR2 and DDR3 depending on the motherboard.

Meanwhile, the Northbridge also provides 16 lanes for PCI-E 2.0 graphics slots, which can either be allocated to one slot, or split across two slots with eight lanes each. As you would expect, the board also supports ATI’s CrossFire technology for combining the power of two graphics cards.

The Northbridge can also support six single-lane PCI-E slots, and a further two can be enabled via the Southbridge. All the other usual extras are also supported by the Southbridge, including support for the legacy IDE and PCI interfaces, plus Gigabit Ethernet and HD audio.

It’s an incremental update, but that’s all we’re going to get until AMD releases its CPUs with integrated graphics. The company has already revealed some of the details of the new architecture, and Kozak assures us that “we’ll be integrating the Northbridge into another chip pretty soon.” He also noted that the new architecture was the main reason why AMD “never went for an MCP type of platform, like Nvidia has done - our future platforms actually require a separate Southbridge.”