According to The Inquirer, SiS will roll out SiS655 chipset for Pentium 4 platforms sometimes in November, a bit later than Intel’s Granite Bay is expected to come. The new product from SiS will support dual-channel DDR SDRAM memory, just like the Granite Bay, but will also provide even more advanced technical specifications.

SiS655 North Bridge will support Intel Pentium 4 processors with 400/533MHz Quad Pumped Bus and probably the Hyper-Threading technology enabled. The novelty will offer dual-channel PC2700 memory controller, providing 5.2GB/s of peak bandwidth, more than the Granite Bay or SiS R658 can give us. It should be pointed out that SiS655 will be able to work in either 128-bit dual-channel mode or in 64-bit concurrent mode. For the former case, you will have to install either two or four totally identical memory modules, while for the latter configuration, you can install any number of DIMMs you would like. As all the latest North Bridges from SiS, this one supports up to 4GB of DDR SDRAM and AGP 8x as well.

The newcomer will be equipped with SiS693 I/O controller, thus, we can expect mainboards based on the described core-logic device to provide 2-channels of Parallel ATA-66/100/133, 6 PCI masters, USB 2.0, FireWire (IEEE1394) ports, AC97 and MC97 as well as integrated 10/100 Ethernet.

Given that DDR-supporting chipsets often costs less than those utilising RDRAM, we can suppose the SiS655 to be cheaper than their R658. Furthermore, the latter only supports dual-channel PC1066 RDRAM, as a result, the theoretical peak bandwidth provided by its memory bus will be around 4.2GB/s, less than SiS655 can offer. Although I cannot be very sure, but there is extremely high probability that the latter will show us better or, at least, equal performance compared to the former. Who will buy the R658 in this case?