Item Via PT894 Via PT880 SiS R659 ALi M1683 Via PT800 SiS 661FX, M661FX SiS 655FX SiS 648FX
Release2005-01-31 2003-11-07 2003-10-07 2003-07-08 2003-07-08 2003-07-01 2003-06-24 2003-05-21
Bus speed 800, 1066 MHz 800 MHz 800 MHz 800 MHz 800 MHz 800 MHz 800 MHz 800 MHz
Memory 1x DDR2 533, DDR400 2 x DDR400 PC1200 RDRAM x 4, 16 GB DDR400 DDR400, 8 GB DDR-400 2 x DDR400 DDR400
Ports VT8237, VT8251, 8x V-Link VT8237 SiS963/SiS964 M1563 VT8237 SiS963/SiS964 SiS963/SiS964 MuTIOL 1G, SiS963L
Processor Pentium 4 Pentium 4 Pentium 4 Pentium 4 Pentium 4 Pentium 4 Pentium 4 Pentium 4
PCI PCI Express x16 PCI 2.2
Graphics PM: UniChrome PM only Real256E
Type Desktop Desktop Desktop Desktop Desktop Desktop, Mobile Desktop Desktop
PCI Express

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.

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.

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.

2003-07-08 ALi M1683 Pentium 4 chipset with support for the 800 MHz bus and single channel DDR400. Uses the M1563 south bridge.

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.

2003-07-01 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.

2003-06-24 SiS 655FX Pentium 4 chipset succeeding the SiS 655 now supporting the 800 MHz bus and dual channel DDR400. Otherwise identical to SiS655

2003-05-21 SiS 648FX Pentium 4 chipset supporting the 800 MHz bus and DDR 400. Identical to SiS 648 otherwise.