Introduction

When we first saw the Intel Pentium 4 introduced and the markets initial reaction to this new technology, I remember thinking to myself, how long until Intel gives us the Pentium 4A or Pentium 5. The Pentium 4 has been the most evolving and changing platform in the history of computer CPU's.

Originally, the Pentium 4 was coupled with the i850 chipset. This was the biggest reason that the market rejected the Pentium 4 CPU. The i850 was designed to run only with PC600 or PC800 RDRAM memory. While RDRAM was a good accompaniment to the Pentium 4, the huge let down that RDRAM gave the Pentium 3 platform still left a sour taste in the consumers mouth, and with the price or RIMM modules being nearly 3x that of a standard PC133 SDRAM module and 2x that of DDR modules, the Pentium 4 was met with a huge groan from the OEM's and consumers alike.

Due to Intel's contract with Rambus stating they would not produce DDR based chipsets, Intel was put into a bind. RDRAM based i850 boards were not selling and the Pentium 4 was costing Intel a huge amount in advertisements. Intel's only recourse was the PC133 SDRAM based i845 chipset.

While Intel was constrained by the Rambus agreements, SiS wasn't. SiS, unlike VIA, didn't tempt Intel and purchased a license to produce chipsets for the Intel Pentium 4 CPU's. They produced the first widely accepted Pentium 4 chipset, the 645. This chipset supported 400MHz FSB, official support for DDR-200/266 memory and unofficial support for DDR-333 memory, well ahead of VIA's support for the same technology.

SiS upped the ante with the 645DX chipset. This supported the 533MHz FSB Intel introduced; official support for DDR-333 memory. This was the biggest DDR chipset sold until the release of the i845D from Intel. SiS' most recent introduction was the 648 chipset. This baby gave 533FSB, unofficial support for DDR-400 and introduced the new 963 Southbridge.

With bandwidth requirements increasing, Dual Channel was the way of the future for DDR based Intel Pentium 4 chipsets. Intel produced the first with the E7205 chipsets. This chipset only allows for up to DDR-266 memory. Thus not giving us any extra headroom.

SiS has pulled a rabbit out of its hat with the SiS655. This is the first Dual Channel DDR chipset from SiS. Today we look at the Gigabyte SINXP1394, the first board to be based on this chipset.