Chip sets revisit AMD prospects
By Brian Dipert -- EDN, November 11, 2004
The last time that ATI Technologies rolled out AMD-targeted core-logic chip sets, AMD was a far less formidable presence in the x86 microprocessor market than it is today (see “Embedded graphics goes with the trends,” EDN, April 4, 2002, pg 22). As a result, ATI’s Radeon 320 IGP companion chips for AMD desktop PCs never entered volume production. ATI concentrated its AMD efforts on mobile-PC opportunities, and the company focused most of its development energy on Intel CPU-based alternative designs employing the 330 and 340 IGP chip sets, along with follow-on Radeon 7000 and 9100 IGP devices.
Fast-forward two and a half years, and the situation is far different: AMD’s Athlon-64 and Sempron CPUs have been tremendously successful, whereas Intel has experienced several high-visibility road-map stumbles, the latest of which is the cancellation of the 4-GHz Pentium 4. As a result, ATI is revisiting the AMD market, and the Radeon Xpress 200 series of chip sets is the outcome of this re-engagement.
The 200G proliferation of the north-bridge chip includes a 300-MHz Radeon X300-derived graphics core that processes two pixels per clock and can run either with a dedicated frame buffer or in UMA (unified-memory-architecture) mode, an approach that is especially challenging with AMD’s CPUs’ integrated DRAM controllers. The pinout-compatible 200P strips out the integrated graphics; both north-bridge proliferations optionally connect to a separate graphics board over a 16-lane PCI Express interface and contain four ×1 PCI Express buses for Gigabit Ethernet and other high-performance interconnect applications.
ATI historically used the 66-MHz, 32-bit, proprietary, PCI-derivative A-Link north-to-south-bridge interconnection in its chip sets. With Xpress 200, conversely, ATI has embraced industry-standard dual-lane PCI Express. The south-bridge chip common to both the 200G and 200P supports four SATA ports with RAID 0 and 1 capability and two PATA ports, eight USB 2.0 links and legacy PCI connections, and AC’97 capability. (It does not yet support high-definition audio.) The production-ready Radeon Xpress 200 family’s flexibility translates to system designs at a range of predicted prices—from less than $700 to several thousand dollars. A mobile spin of Xpress 200 is on the way, along with Intel-CPU-tuned desktop and mobile variants of the architecture, which should debut early next year.
ATI Technologies, 1-905-882-2600, www.ati.com.
