The 655FX reference motherboard is about 2 cm longer then regular sized ATX motherboards and has several ports and connectors you are unlikely to find on any other board. The SiS 655FX Northbridge generates a fair amount of heat under power, but only a small active cooler is required to keep it operational. The SIS 964 southbridge does not feature any type of cooling attachment, though there are mounting holes which suggest that option is necessary in some circumstances.

The new SiS 964 Southbridge supports enhanced Ultra/133 data transfers (we'll get more into that in a bit) as well as two Serial ATA/Serial ATA RAID (0 and 1 support). The SIS964 also natively supports 10/100 LAN as well as 1/10 Mb HomePNA (Phone Line) controller and eight USB 2.0 ports.

The SIS964 does get quite warm during operation, so it wouldn't surprise me to see manufacturers place a passive heatsink on the Southbridge in the future.

To enable the dual channel memory architecture you need to install the system memory in pairs and they must go in alternating DIMM slots.