SiS 645

SiS 645
Name	SiS 645
Maker	Silicon Integrated Systems
Launch	2004
Type	motherboard chipset
Supported CPU	Intel Pentium 4, Intel Celeron, Intel Pentium M (with adapter)
Northbridge	SiS 645 Northbridge
Southbridge	SiS 964, SiS 963
Memory	DDR, DDR2 (depending on revision)
Pci express	x16 (implementation details vary)

SiS 645 The SiS 645 was a central chipset released by Silicon Integrated Systems in 2004 targeting desktop platforms around the Intel Pentium 4 and mainstream Intel Celeron processors. It aimed to provide an integrated graphics solution and support for emerging technologies such as PCI Express and DDR2 memory, competing with chipsets from Intel Corporation, NVIDIA Corporation, and Advanced Micro Devices. The chipset saw adoption in various systems by manufacturers like ASUS, MSI, and AOpen and was discussed in reviews by outlets including Tom's Hardware, AnandTech, and PC Magazine.

Overview

The SiS 645 combined an integrated graphics controller and a memory controller hub intended for mainstream desktop boards sold during the transition from Socket 478 to LGA 775 platforms. It was positioned as a cost-effective alternative to chipsets from Intel Corporation and NVIDIA Corporation used in systems by Dell, HP, and boutique builders like Falcon Northwest. Analysts at Gartner and journalists from CNET tracked its market penetration as part of the broader chipset competition in the early 2000s.

Architecture and Features

The chipset integrated a northbridge with an onboard graphics core derived from previous SiS designs and a southbridge partner such as the SiS 963 or SiS 964, providing I/O functionality for peripherals from vendors like Creative Technology and Realtek. It offered support for DDR and later DDR2 SDRAM standards, a single PCI Express x16 slot for discrete graphics, multiple PCI slots, and integrated ATA/RAID controllers used in configurations by Western Digital and Seagate Technology. The graphics engine competed with integrated solutions from Intel Graphics Technology and entry-level GPUs from NVIDIA GeForce and ATI Technologies (now AMD), and supported video outputs leveraged by Samsung and LG Electronics monitors.

Chipset Variants and Revisions

Silicon Integrated Systems produced revisions to address compatibility and feature sets, including variants paired with different southbridges (SiS 963, SiS 964) and stepping updates to improve DDR2 support and bug fixes noted by reviewers at AnandTech and maintenance bulletins from OEMs such as Acer and Lenovo. Some motherboard makers released BIOS updates to improve support for Intel Pentium M processors in mobile-to-desktop adaptations, and community projects documented quirks across boards from ECS and Gigabyte Technology.

System Compatibility and Platforms

The SiS 645 was compatible with mainstream desktop sockets of the era, primarily supporting LGA 775 Pentium 4 and compatible Celeron CPUs, and could be found in systems running Microsoft Windows XP, Linux distributions like Debian and Red Hat Enterprise Linux, and embedded builds used by vendors such as Fujitsu Siemens Computers. OEM integrators like IBM (PC division), Gateway, Inc., and small form factor designers adapted boards with this chipset for entry-level desktops and multimedia PCs.

Performance and Benchmarks

Independent testing by publications such as Tom's Hardware, AnandTech, and PC World measured the integrated graphics against competitors from Intel Corporation and VIA Technologies. Benchmarks in titles and suites common to the period (for example, testing by Future plc outlets) showed the SiS integrated GPU lagging behind discrete solutions like the NVIDIA GeForce 6 series and integrated rivals in 3DMark and multimedia playback, while offering adequate performance for office applications used with Microsoft Office and web content viewed in Mozilla Firefox and Internet Explorer. Memory throughput comparisons versus contemporary chipsets from Intel and NVIDIA Corporation revealed trade-offs between cost and bandwidth, influencing choices by system integrators such as eMachines.

Driver Support and Software Integration

Driver distribution for SiS 645 came from Silicon Integrated Systems and was integrated into OEM driver packs provided by companies like ASUS, MSI, and AOpen; community support and custom drivers were discussed on forums hosted by Tom's Hardware, Overclock.net, and Linus Tech Tips contributors. Supported operating systems included Microsoft Windows XP, various Linux kernels with vendor or community-maintained modules, and compatibility layers used by projects such as Wine for legacy application support. Software integration for media playback relied on codecs and players produced by firms like DivX, Inc. and CyberLink.

Legacy and Historical Impact

Though not a market leader, the chipset played a role in the transition period to PCI Express and DDR2 memory, illustrating trade-offs between integrated graphics and discrete GPUs from NVIDIA Corporation and AMD. Its presence in budget systems sold by Dell, HP, and OEMs such as Acer influenced cost-sensitive segments and spurred discussions in publications like PC Magazine and Maximum PC about platform value versus performance. Enthusiast and preservationist communities, including archives maintained by The Internet Archive and posts on GitHub, have documented driver packages and BIOS updates for legacy support.

Category:Motherboard chipsets Category:Silicon Integrated Systems