The SiS655FX features an AGP 8X bridge, and Dual-Channel DDR400 Memory controller, supporting Pentium® 4 FSB up to 200MHz. The SiS655FX, via the second-generation 1GB/s Multi-threaded I/O link, interconnects the SiS964 Media I/O that integrates one EHCI compliant USB 2.0 host controller, 3 OHCI compliant USB 1.1 host controllers, the SATA 150 controller, the ATA 133 dual IDE controller, AC'97 v2.3 compliant audio controller, and the Ethernet MAC controller with standard MII interfaced.

The SiS655FX Host Interface features the AGTL & AGTL+ compliant bus driver technology with integrated on-die termination to support Intel® Pentium® 4 series processors with FSB up to 800MHz. The AGP interface supports external AGP slot with AGP 4X/8X capability and Fast Write Transactions. The SiS655FX incorporates the second-generation 1GB/s MuTIOL® interface to bridge the SiS964 Media I/O. SiS MuTIOL® technology is developed into three layers, namely the MuTIOL® transaction layer, MuTIOL® link layer, and the MuTIOL® physical layer.

The SiS655FX Dual-Channel Memory Controller, being the best Pentium® 4 chipset in the worldwide that delivers 6.4 GB/s bandwidth way adequate and satisfactory to the 800MHz Pentium® 4 FSB bandwidth demand of 6.4GB/s, absolutely brings out the best performance of each other, and still has a lot to spare for the multi-I/O masters, and AGP masters. Foremost, based on the SiS655FX with optimized ball-out, a Pentium® 4 system featuring the Dual-Channel memory subsystem can be realized in a cost-effective 4-layer PCB.