890FX chipset
With the Phenom II X6 and Radeon HD 5800-series cards out in the wild, the 890FX chipset is the final part of the new high-end platform known as Leo. We expect Leo to be the backbone of the very best VISION Black systems built by system integrators.
So what makes 890FX tick, and how is it different to the 790FX that's been the headline chipset for over a year now.
RD890
High-end consumer chipsets are all about no-limit performance. That's why the 65nm 890FX ships with a total of 42 PCIe lanes, of which 32 are used for graphics in numerous CrossFire configurations - including two cards at x16, x16 or four cards at x8, x8, x8, x8. The remainder are arranged as a x4 slot and a further six are dedicated to running PCIe x1 components. 890FX, then, is very well-endowed in terms of lane arrangement, beating out Intel's X58's 36.
Notice the IOMMU reference? The chipset supports an Input/Output Memory Management Unit, often seen on server-level products, that sits inbetween devices and system memory. It works best in virtualised environments where, traditionally, virtualised machines use emulated drivers to access physical devices. IOMMU enables the virtualised 'guest' OS to use a peripheral's native driver without resorting to emulation, thereby providing a more-direct approach.
SB850
The real action lies with the SB850 southbridge, though. First seen with the 890FX chipset, it connects to the northbridge via a 4GB/s A-Link Express III interface, and it has the bandwidth to facilitate a wide range of current-generation interfaces including six SATA 6Gbps ports, Gigabit Ethernet, and 14 USB 2.0 ports, and a further two full-bandwidth PCIe lanes. SuperSpeed USB 3.0 doesn't feature as standard, but you can expect most manufacturers to offer USB 3.0 ports via a third-party controller, usually NEC's.
AMD's 890FX chipset is an obvious update to the company's 790FX. A slight bump in northbridge specification is augmented by a significant boost in the southbridge. The combination of RD790 and SB850 makes 890FX the most feature-rich consumer chipset to date.
