The SiS671, supporting Core 2 Duo/Pentium® D/Pentium® 4 series processor with Hyper-Threading Technology and FSB up to 800MHz, features a PCI Express x16 Bridge, flexible Single-Channel DDR2-667 Memory controller, Mirage™ 3 graphic engine, and SiS MuTIOL® Technology, which connects with the SiS968 MuTIOL® Media I/O.

The integrated SiS Mirage™ 3 GPU features a high performance graphics engine supporting DX9 2.0 and D3D9.L features, a video accelerator, a MPEGI/II motion compensation decoder, and a video link (shared with PCI Express x8 lane) to support the TV-out & digital flat panel. The SiS671, adopting the Shared Memory Architecture, eliminates the need and thus the cost of the frame buffer memory by organizing the frame buffer size up to 256MB in the system memory.

The PCI Express is a new standard of I/O interconnect. It has several advantages over legacy PCI. Furthermore, it is PCI compatible in software. The SiS671 integrates a X16 Host-to-PCI Express bridge that is compliant with PCI Express SPEC 1.1. It also has lane reversal capability to provide maximum flexibility.

The Host interface can support the Core 2 Due/Pentium® D/Pentium® 4 series CPU with bandwidth up to 6.4GB/s. It also supports CPU with Hyper Threading Technology and FSB 1066MHz. The Sis671 support Single Channel Memory Controller, providing bandwidth up to 5.3GB/s at DDR2-667.

SiS MuTIOL® technology is developed into three layers: the Multi-Threaded I/O Link Layer delivering 1.2GB/s bandwidth to connect embedded DMA Master devices and external PCI masters to interface with the Multi-Threaded I/O Link Layer, the Multi-Threaded I/O Link Encoder / Decoder in SiS968 to transfer data at 1GB/s bandwidth from / to the Multi-Threaded I/O Link Layer to / from the SiS671, and the Multi-Threaded I/O Link Encoder / Decoder in the SiS671 to transfer data at 1GB/s from / to memory sub-system to / from the Multi-Threaded I/O Link Encoder / Decoder in SiS968.