Micron Announces New Pentium III and DDR SDRAM Chipset

In mid-1997, Micron introduced its own chipset for the Pentium II, which they named ‘Samurai’. This chipset was used in the Micron Powerdigm XSU workstation, targeted at the server market and offered support for 64-bit PCI-X rather than AGP. Unfortunately for Micron, the industry adopted AGP, and the demand for the chipset was limited. In late 1999, Micron included support for 133MHz FSB and DDR SDRAM. Only last Fall, several publications reported that the Samurai chipset would be dropped by Micron in favor of the Mamba chipset, which uses embedded eDRAM for L3 cache.

Today, Micron announced a prototype of the Copperhead chipset for servers using Pentium III processors, which is based upon the Samurai chipset. Micron is able to offer this chipset due to an agreement with Intel that was signed in late 2000. Samples and reference platforms are expected to ship in the first half of this year, with production to follow in the second half. A demo system based upon this chipset will be shown at the Intel Developer Conference this week.

The Northbridge (Copperhead) has been enhanced to support the newest Pentium III processors, up to 8GB of Registered (4GB Unbuffered) PC1600 and PC2100 DDR SDRAM in 4 DIMM slots, as well as both PCI-X and PCI 2.2. The Southbridge (Coppertail) supports two ATA/100 IDE ports, four USB ports (rev 1.0), and various ‘legacy’ features. ISA is not supported, however. The chipset initially will require 6-layer boards.

Both PCI 2.2 and PCI-X support 64-bit data transfers, however PCI 2.2 is limited to 66MHz, while PCI-X operates at 66, 100 or 133MHz. The Northbridge will also support DDR SDRAM chips in densities up to 512Mb, yielding modules of 512MB or 1GB in size. Figure 1 shows the basic chipset design.

Figure 1 – Copperhead Chipset (courtesy of Micron Technology, Inc.)

Just as Samurai was, Copperhead is being presented as an enablement chipset for DDR memory technology. Though reportedly not actively pursuing the chipset market, a Micron representative has indicated that commercial shipments are possible if there is sufficient market demand.