VIA Apollo P4X333 Chipset White Paper
VIA Apollo P4X333 Chipset
Enabling Total System Performance
High performance DDR333 chipset platform for the
Intel® Pentium® 4 processor
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Introduction
The VIA Apollo P4X333 is a core logic chipset solution that makes Total System
Performance a reality in Intel® Pentium® 4 processor based systems. Fusing the
unequalled bandwidth of DDR333 with the Intel® Pentium® 4 processor, the VIA
Apollo P4X333 with 533MHz processor bus, AGP 8X, ATA-133, USB 2.0 and Double-
Speed V-Link chip interconnect, brings an unmatched suite of new memory, system
and I/O technologies to a single platform. In combination these technologies enable
Intel® Pentium® 4 systems and servers to achieve heights of performance never
scaled before.
In the past, advances in one area of system performance have frequently been held
back by I/O and connectivity bottlenecks, but with the advent of the VIA Apollo
P4X333, every aspect of performance is addressed, delivering end user experiences
that meet the high expectations of today’s consumers. The VT8235, with USB 2.0
integrated into a chipset for the first time, enables peripheral devices to send and
receive data at 480 Mbps, 40 times faster than the previous USB standard. This data
can then be sent to the North Bridge through the new Double-Speed V-Link chip
interconnect which offers 533MB/s of bandwidth, twice as much as Intel Hub
Architecture, making sure the ultra fast processor and DDR333 memory subsystem
is supplied with all the data it needs minimizing system delays and offering the
smoothest system performance you will ever have experienced.
The flexibility of V-MAP architecture means the VIA Apollo P4X333 is pin to pin
compatible with the previous generation VIA Apollo P4X266A, enabling it to leverage
the huge choice of motherboard configurations already developed, enabling a fast
time to market and lower development costs, ultimately delivering value to the end
user.
The launch of the VIA Apollo P4X333 further extends the leadership role that VIA has
played in enabling rapid industry wide transitions to higher bandwidth memory
technologies that enable OEMs and SIs to address a performance hungry market and
support today’s and tomorrow’s most demanding applications. It achieves total
system performance through the implementation of the following key technologies:
• DDR200/266/333 SDRAM Support: The VIA Apollo P4X333 features the
world’s fastest single channel memory controller, designed for exceptionally
high performance. Supporting DDR200/266/333 memory, the VIA Apollo
P4X333 provides lightning fast access to system memory and can reach a
peak bandwidth of 2.7GB/sec, 25% greater than the P4X266A, enabling the
full performance potential of the fastest Intel® Pentium® 4 processors to be
harnessed.
• 400/533MHz Processor Bus Settings: The VIA Apollo P4X333 has the
fastest ever processor bus, extending to 533MHz to keep even the highest
speed grade Intel® Pentium® 4 processors supplied with as much data they
can handle. The P4X333 processor bus is flexible with a 400MHz speed setting
for processors locked to that level.
• AGP 8X: New AGP 8X technology implented in the VIA Apollo P4X333 North
Bridge conforms to the full AGP 3.0 specification and provides up to 2.1GB/s
in graphics bandwidth, deriving maximum performance from current and
future graphics processors and making the P4X333 the ultimate platform for
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game enthusiasts and design professionals. Additionally, it does not sacrifice
AGP 4X compatibility, allowing low cost graphics products to be paired with
Intel® Pentium® 4 systems for everyday computing in business &
educational and home environments.
• Double-Speed V-Link: The VIA Apollo P4X333 is equipped with new Double-
Speed V-Link Chip interconnect between North and South Bridge. Double-
Speed V-Link offers 533MB/s of memory bandwidth, 4 times as much as less
advanced chipsets which use the 132MB/s PCI bus as a link.
• USB 2.0: The superior bandwidth capacity of Hi-Speed USB 2.0 is integrated
into the VT8235, providing transfer speeds 40 times faster than the standard
USB 1.1 specification. This high-speed transfer technology is ideal for today’s
bandwidth-hungry peripherals such as video cameras and next generation
scanners and printers, and greatly enhances the performance of demanding
applications such as interactive gaming and digital photography.
• ATA-133 IDE Interface: ATA-133 FastDrive™, integrated into the VT8235
South Bridge is the fastest IDE interface currently available and meets today’s
ever increasing data transfer requirements offering shorter access times and
greater performance in a huge variety of everyday applications including
audio, video & gaming.
• V-MAP: The VIA Modular Architecture Platform offers a balance of reliability
and flexibility. Reliability comes from using proven, modular components and
evolutionary design principles in enabling the VIA Apollo P4X333 to share the
best characteristics of award winning previous generation products like the
VIA Apollo P4X266A. Flexibility comes from the pin compatible North Bridge
enabling motherboard manufacturers to save development costs and speed
P4X333 solutions to the market.
This white paper describes the features of the VIA Apollo P4X333 chipset in detail as
well as the elements of total system performance that enable next generation
computing for high performance desktops, workstations, and servers based on the
Intel® Pentium® 4 processor.
DDR333: The Power of Evolution
VIA Technologies, Inc. has been instrumental in driving new memory technologies to
the market by being the first company to offer PC133 based chipsets to the
marketplace, and the first company offer DDR SDRAM based chipsets for Socket 370
(Intel® Pentium® III, VIA C3™), Socket 423/478 (Intel® Pentium® 4) and Socket
A (AMD Athlon™ and AMD Duron™) platforms.
DDR SDRAM was developed to keep pace with newer, more powerful PC processors
like the AMD Athlon™ XP and Intel® Pentium® 4 which require faster access to the
system memory to deliver to their full performance potential. Compared to
PC100/133, DDR doubles the effective clock rate by transferring data on both the
rising and falling edges of the clock. Also, due to its evolutionary, parallel
technology, the latency of DDR is quite low compared to competing serial memory
technologies like RDRAM.
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All grades of DDR SDRAM operate at 2.5 volts, as opposed to 3.3V for PC100 and
PC133. This lowered voltage allows DDR to penetrate power sensitive applications,
such as notebooks and 1U servers. Lowered power consumption translates directly to

VIA P4X333 是一款专为Intel 400系列（如Pentium 4）架构主板设计的南桥芯片组。它是由 VIA Technologies, Inc.（威盛科技股份有限公司）生产的，主要应用于个人计算机主板上，作为英特尔 i486DX/PII/PIII/P4 等处理器的扩展平台。 P4X333 芯片组的核心功能包括对PCI Express x16、AGP 4x以及多个PCI插槽的支持，能够提供足够的扩展性以连接各类显卡、声卡、网卡等外设。此外，它还集成了USB 2.0、IEEE 1394 (FireWire) 接口控制器，以及其他诸如IDE/SATA接口控制电路，使得主板能支持多种存储设备的高速数据传输。 在内存方面，P4X333 支持 DDR SDRAM，并通过南北桥之间高性能的 HyperTransport 总线与CPU交换数据，从而保证了系统整体性能的发挥。同时，该芯片组具备一定的集成网络功能，例如整合了VIA Fast Ethernet 控制器，可实现千兆位以太网通信。 总之，VIA P4X333 芯片组凭借其良好的兼容性和丰富的扩展能力，在当时的计算机市场中得到了广泛的应用，对于提升当时桌面系统的整体效能和便捷性做出了积极贡献。