2003-05-21 SiS 648FX Pentium 4 chipset supporting the 800 MHz bus and DDR 400. Identical to SiS 648 otherwise.
2003-07-01 SiS 661FX, M661FX Chipset for Pentium 4 with the 800 MHz bus. Supports single channel DDR400 and includes integrated graphics. Mass production in August and motherbords expected in September. The earlier rumoured 660FX chipset is believed to have been scrapped as it was too similar to the 661. Now (03-07-31) also available in a mobile, M661FX version.
2003-07-08 Via PT800 Pentium 4 chipset with support for the 800 MHz bus. Earlier known as PT400. Uses the 8237 south bridge. Will also be available in a PM800 version with integrated UniChrome graphics available in Q4.
2003-10-07 SiS R659 Pentium 4 chipset supporting four channel RDRAM at 1200 MHz for a bandwith of 9.6 GB/s. To be complemented by the SiS963 / SiS964 south bridges. Launched in July, mass production in November.
2003-11-07 Via PT880 Pentium 4 chipset previously known as PT600 supporting the 800 MHz bus. Identical to PT800, except for an added second DDR400 channel. Includes QBM 533 support, which seem to be two DDR channels with one delayed by 90 degrees. Uses the VT8237 south bridge. There will also be a PM880 version with added UniChrome graphics launched in 04-Q1.
2005-01-31 Via PT894 Pentium 4 chipset earlier known as PT800 / PT890 supporting the 1066 MHz bus and 666 MHz DDR2. Uses the VT8237, and VT8251 south bridges. Includes PCIe x16 support while the PT894PRO version will include 2 PCIe links (to be run as x16 + x4 or 8x + 8x).
There will also be a PM890 / PM894 version with added DeltaChrome IGP (previously known as UniChrome 3) graphics launched later.