There are clear indications that the latest core-logic for desktop computers with RDRAM support from Silicon Integrated Systems will never see the light of the day, as ASUSTeK, the only mainboard maker who planned to release a product powered by the technology is pulling back.

SiS R659 – Do We Need More Than We Actually Need?

A report over EETimes web-site claims that ASUS and SiS had abandoned their project to release the R659 core-logic into the market. The claim does not have any official confirmations at this time, but based on the information X-bit labs has about the status for the Socket 478 P4S13G mainboard from ASUS, the news-story by the web-site seems to have the ground.

SiS R659 core-logic is designed to provide 4-channel RDRAM PC1200 and is able to sport up to 9.60GB/s of peak memory bandwidth – more than enough for present and future Intel Pentium 4 processors with 800MHz Quad Pumped Bus. The chipset also includes architectural enhancements for higher performance through faster response time, a feature SiS calls Advanced HyperStreaming. In total SiS’ R659 supports up to 16GB of memory, even though conventional Intel Pentium 4 processors do not address more than 4GB of memory. The R659 North Bridge is to be coupled with the SiS964 I/O controller, which integrates 8 USB 2.0 ports and Serial ATA-150 RAID features.

ASUS showcased its feature-rich P4S13G mainboard during the Rambus Developer Forum in Taipei, Taiwan in November 2003 and also demonstrated some performance figures of the R659. According to preliminary benchmarks, a system powered by R659 runs Quake III-based games about 7% faster than a comparable computer, but based on i875P chipset. The R659 does not give any significant advantages in office applications, but provides from 4% to 12% speed increase under workstation software workload.

SiS, ASUS and Samsung have been talking about the R659 chipset since the first quarter 2003, but the actual mainboard powered by the world’s last RDRAM-supporting chipset was finally scheduled for December release. However, neither reviewers nor retail customers received the latest RDRAM-based product.

The reasons for the move to pull back the R659 are pretty clear – the chipset is pretty expensive and does not provide substantial performance benefits in addition to new technologies like PCI Express.

RDRAM, The Saga Continues?

However, SiS is likely to continue developing chipsets with support for Rambus memory. Earlier this year there were claims about SiS R659FX and SiS R659TX coming out in the Q3 2004 and Q1 2005 respectively. Both parts sport 400, 533 and 800MHz processor system bus, PCI Express x16 interface for graphics cards as well as quad-channel RDRAM memory controllers. The difference between the two chipsets is expected to be the maximum speed of memory the core-logic can handle. The “FX” is designed to work with PC1333 RDRAM, the “TX” is intended for PC1600 RDRAM.

Prospects of RDRAM on the market of desktop and mobile personal computers have always been pretty unclear. Expensive memory with no actual advantages was not a logical choice for the majority of clients who tend to use cost-effective solutions. Silicon Integrated Systems has developed, but has not released already two chipsets that supported RDRAM memory – the R658 and the R659. Meanwhile the Rambus memory is eroding from the market, the question about possibilities for the next-generation core-logic sets with RDRAM support to be released commercially seems to have a pretty obvious answer.