Most know SIS as being the producer of value segment computer chipsets, while
it used to be true, a while ago, SIS today is getting into a more serious
market with its latest solutions for the Pentium 4 and AMD Athlon processors.
new SIS 645 for the Pentium 4 is quite a unique solution with its support
for DDR333 memory which is capable of driving a bandwidth of up to 2666MB/s;
higher than any DDR support available on todayís Intel and VIA chipsets. The
North Bridge offers support for SDRAM as well as
DDR266 and DDR200; most boards featuring the SIS 645 will likely take care
of DDR due its higher bandwidth over SDRAM. The transfer protocol between
the North and South Bridge is designed for multiple isochronous virtual channels,
its 16-bit bus wide bus running at 266MHz provides a fully bi-directional
channel that transfers data at up to 533MB/s. Feature provided by the South
Bridge include the practically the same you would expect from an Intel ICH2
or VIA South Bridge, features include ACĒ97 v2.2 audio, ethernet, dual channel
USB offering up to six USB 1.1 Ports and IDE Ultra ATA 100 support.
Overclocking the Northwood
With its new 0.13 process the Northwood is a processor with great overclocking
potential. Our board of choice was the Soltek 85DRV P4X266 due its great overclocking
features. We easily pushed our 2.2GHz unit on a 126MHz Quad Pumped Bus speed
resulting in 2772MHz. We only added 0.5V to the processor, quite impressive.
The 2000MHz part touched 126MHz as well using the same Vcore bump, thatís