X-bit labs

SiS Announces 4-Channel RDRAM Core-Logic, but Is About to Lose its QPB License.

Category: Chipsets

by Anton Shilov

[ 01/31/2003 | 11:19 AM ]

SiS’ intention to occupy the largest market share of core-logic sets possible definitely deserves our respect. A not really big Hsinchu, Taiwan-based company managed to dramatically strengthen their market position in one year and plans to expand the share even further.

Last year SiS unveiled their R658 chipset with RDRAM support destined for high-performance desktop and workstations computers. Although the product has not been adopted by largest mainboard makers yet, SiS now plans to roll-out another Rambus supporting chipset by the end of the year. This week SiS announced its next-generation SiSR659 core-logic, designed to support four-channel RDRAM PC1200. The R569 North Bridge will be coupled with the SiS964 I/O controller, which integrates 8 USB 2.0 ports and Serial ATA-150 features. Samples of the SiSR659 are scheduled to come in the third quarter 2003.

The R659 North Bridge will be able to provide up to 9.6GB/s of memory bandwidth thanks to the four-channel memory controller with PC1200 RDRAM support. Even the forthcoming Pentium 4 CPUs with 800MHz Quad Pumped Bus require just 6.4GB/s. Moreover, the Pentium 4 processors with 1066MHz Quad Pumped Bus would consume about 8.5GB/s, while 9.6GB/s peak bandwidth is only necessary with 1200MHz Quad Pumped Bus. As far as I know, the Prescott processors are still intended for 800MHz Quad Pumped Bus, thus, there will be no need for such advanced core-logic for the CPUs this year. On the other hand, there is another 90nm babe to come in 2004: the code-named Tejas processor. As this one is going to be the crown of the Pentium 4 and maybe even the Net Burst architecture, Intel may really introduce the 1200MHz Quad Pumped Bus for it. This is only an early assumption, as there are some concerns about the availability of high-speed (300/600MHz) DDR-II chips in 2004 and, as we know, (see this news-story), Intel wants to utilise DDR-II in their upcoming chipsets. Summing everything up, we can point our that the whole R659 is about the future Intel processors, not present or even upcoming CPUs, even if we suppose that the Prescott chips’ QPB will be shifted to 933 or even 1066MHz. Maybe SiS simply wants to develop their own chipset for the Xeon processors that support dual-CPU configurations and may require higher memory bandwidth.

Unfortunately, not everything is good about SiS these days. As reported over here, Intel may refuse to provide SiS the license on the next-generations Quad Pumped Bus because of SiS’ recent relationship with UMC. We already told you that the latter owns 15% share in SiS (see this news-issue) and also plans to make CPUs for AMD. Hence, Intel may withdraw the license in order not to support AMD even indirectly. The information is strictly unofficial, but in case Intel will really not allow SiS to sell higher-end Pentium 4 intended chipsets, all the hype around the R659 and other future products is nothing but a vain enterprise.