In recent months, SiS has been surprising us with its chipsets, which have equaled or even outperformed those from Intel. The major advantage of this Taiwanese manufacturer is, as always, its aggressive pricing policy. Its latest product is the 655 chipset with dual DDR333.

Chipset development is always demand-driven. The SiS645 supported 333 MHz DDR RAM early on. Shortly afterwards came the revised 645DX, which offered greater performance. The previous top model was the SiS648, which also supports the faster Pentium 4 models with 533 MHz FSB. SiS chipsets have provided support for DDR400 for six months now but, because of the absence of a JEDEC specification and its negligible performance benefits, this memory has not officially been released up to now.

SiS has kept pace with developments in I/O components. So far, there have only been four devices for the Pentium 4 (961, 961B, 962 and 963). Common to all of these are the PCI controller, multichannel audio, network interface, ACPI controller, real-time clock, IDE controller and a total of six USB ports. The 961B was the first to offer Ultra ATA/133; the 962 provided USB 2.0 and a FireWire interface, and the current 963 also offers a faster pipeline to the Northbridge (one gigabyte per second instead of 533 MB/s).

SiS is breaking new ground with the introduction of a dual-channel interface for DDR SDRAM, although Intel got there first with the E7205, alias Granite Bay, last autumn, and half a year before that, it came out with the server chipset E7500. With its support for DDR333, we would expect the SiS655 to clearly outperform the Intel E7205. Let's find out!