VIA Chipsets for Athlon, Duron, and Athlon XP

VIA Technologies, Inc., is the largest chipset and processor supplier outside of Intel and AMD. Originally founded in 1987, VIA is based in Taipei, Taiwan, and is the largest integrated circuit design firm on the island. VIA is a fabless company, which means it farms out the manufacturing to other companies with chip foundry capability.

Although it is best known for its chipsets, in 1999 VIA purchased the Cyrix processor division from National Semiconductor and the Centaur processor division from IDT, respectively, thereby becoming a supplier of processors in addition to chipsets.

VIA has also formed a joint venture with SONICblue (formerly S3) as a means of integrating graphics capabilities into various chipset products. This joint venture is known as S3 Graphics, Inc. VIA makes chipsets for Intel, AMD, and Cyrix (VIA) processors.

More recently, VIA has converted to a new architecture called V-Link, which uses a fast dedicated connection between the North Bridge and South Bridge. V-Link is similar to Intel's hub architecture, as well as HyperTransport (used by ALi, NVIDIA, and ATI) and A-Link (used by ATI). V-Link is also used by VIA's Pentium 4 chipsets.

As with VIA's chipsets for the Pentium 4, V-MAP uses identical pinouts for the V-Link North and South Bridge chips so vendors can reuse a motherboard design with more advanced chipsets as they are developed.

VIA Technologies Apollo KX133

The VIA Apollo KX133 chipset brings AGP 4x, PC133, a 200MHz FSB, and ATA-66 technologies to the AMD Athlon processor platform, exceeding the performance of AMD's own 750 chipset. It was the first chipset to support AGP 4x.

Key features include the following:

  • 200MHz processor bus

  • AGP 4x graphics bus

  • PC133 SDRAM memory

  • 2GB maximum RAM

  • ATA-66 support

  • Four USB ports

  • AC97 link for audio and modem

  • Hardware monitoring

  • Power management

The VIA Apollo KX133 is a two-chip set consisting of the VT8371 North Bridge controller and the VT82C686A South Bridge controller.

VIA Technologies Apollo KT133 and KT133A

The VIA Apollo KT133/A chipsets are designed to support the AMD Athlon and Duron processors in Socket-A (462) form. Based on the prior KX133 chipset, the KT133/A differ mainly in their support for Socket-A (462) over the previous Slot-A processor interface.

The VIA Apollo KT133 and KT133A are both two-chip sets consisting of the VT8363 North Bridge and the VT82C686A South Bridge (KT133) or the VT8363A North Bridge and the VT82C686B South Bridge (KT133A).

Both the KT133 and KT133A support the following standard features:

  • Athlon/Duron Socket-A (462) processors

  • 200MHz CPU (front-side) bus

  • AGP 4x

  • 2GB RAM maximum

  • PC100/PC133MHz SDRAM

  • PCI 2.2

  • ATA-66

  • USB support

  • AC-97 audio

  • Integrated Super I/O

  • Integrated hardware monitoring

  • ACPI power management

The KT133A (VT8363A North Bridge with VT82C686B South Bridge) adds the following features:

  • 266MHz CPU (front-side) bus

  • ATA-100

ProSavage PM133

The VIA ProSavage PM133 integrates S3 Graphics' S3 Savage 4 and S3 Savage 2000 3D and 2D graphics engines with the Apollo Pro KT133 chipset. The major features of the chipset are the same as for the Apollo Pro KT133, with the following additions:

  • 2MB–32MB shared memory architecture integrated with Savage 4 3D and Savage 2000 2D video

  • Z-buffering, 32-bit true-color rendering, massive 2K-by-2K textures, single-pass multiple textures, sprite antialiasing, and other 3D features

  • Support for DVD playback, DVI LCD displays, and TV-out

  • PCI 2.2 compliance

An optional AGP 4x interface enables the integrated AGP 4x video to be upgraded with an add-on card if desired. This two-chip chipset consists of the VT8365 North Bridge and VT8231 South Bridge.

The VT8231 South Bridge integrates the Super I/O and supports the LPC interface.

Apollo KT266 and KT266A

The Apollo KT266 is the first VIA chipset for Athlon-based systems to support VIA's high-speed V-Link system architecture. V-Link connects the 552-pin VT8366 North Bridge to the 376-pin VT8233 series South Bridge with a 266MBps data pathway, which is twice as fast as traditional PCI-based connections.

Major features of the KT266 include system bus speeds of 200/266MHz, AGP 2x/4x interface, and up to 4GB of DDR200/266 DDR SDRAM or PC100/133 SDRAM. Other features vary with the South Bridge (VT8233, VT8233A, or VT8233C) chip used with the VT8366.

The KT266A is a pin-compatible upgrade to the original KT266's North Bridge. The KT266A's VT8366A includes VIA's Performance Driven Design, which is not a technical term but a marketing term for the A-series' chips improved memory timing and deeper command queues to improve chipset performance. Basic features of the KT266A are otherwise similar to the KT266.

ProSavage KM266

The ProSavage KM266 combines the features of the KT266 with the graphics core of the S3 Graphics ProSavage 8 2D/3D accelerator. Unlike some other chipsets with integrated graphics, the P4M266 retains an AGP 4x slot, so users can upgrade to faster AGP 4x graphics in the future.

The ProSavage8 core uses 32MB of system RAM for its frame buffer, supports AGP 8x bandwidth internally with 128-bit data paths, and features DVD DXVA Motion Compensation to improve the quality of DVD playback. It supports all members of the VT8233 family of South Bridge chips and has a 266MBps 4x V-Link connection between North and South Bridge chips.

Apollo KT333

The Apollo KT333 is a pin-compatible development of the KT266A, adding support for a 333MHz system bus, 333MHz memory bus, and DDR333 memory. Unlike the KT266A, the KT333 no longer supports PC100/133 memory, but it uses the same KT8233 family of South Bridge chips.

Apollo KT400

The Apollo KT400 is the first VIA chipset for the Athlon XP processor to offer AGP 8x and a second-generation 533MB/s V-Link connection to the South Bridge. It uses the new VT8235 South Bridge, which is VIA's first South Bridge chip to support USB 2.0 as well as ATA-133.

The combination of faster video, fast memory and system bus speeds, and faster V-Link connections make the KT400 among the fastest Athlon XP chipsets.

Apollo KT400A

In previous A-series chipsets from VIA, the North Bridge component was replaced with an improved chip and the South Bridge component was retained. However, the KT400A features new designs for both its North Bridge (VT8377A) and South Bridge (VT8237) chips. Its major features include

  • System bus support up to 333MHz

  • DDR memory support up to DDR400

  • Up to 4GB of memory

  • An expanded array of prefetch buffers to reduce memory latency and improve throughput (FastStream64)

  • AGP 8x interface

  • Integrated six-channel Surround Sound AC'97 audio

  • Eight USB 2.0 ports

  • Integrated MC'97 modem

  • Integrated 10/100 Ethernet

  • Serial ATA

  • ATA 33/66/100/133

  • ACPI/OnNow power management

KT400A's FastStream64 enables the system to reach 3.2GBps memory transfer speeds without the need for more expensive dual-channel memory support.