VIA Apollo P4X400 Chipset White Paper
VIA Apollo P4X400 Chipset
Enabling Total System Performance
High performance DDR400 chipset platform for the
Intel? Pentium? 4 processor
Page 1VIA Apollo P4X400 Chipset White Paper
Introduction
The VIA Apollo P4X400 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 DDR400 with the Intel? Pentium? 4 processor, the VIA
Apollo P4X400 with 533MHz processor bus, AGP 8X, ATA-133, USB 2.0 and 8X 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
P4X400, 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 8X 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 launch of the VIA Apollo P4X400 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:
?? DDR200/266/333/400 SDRAM Support: The VIA Apollo P4X400 features
the world’s fastest single channel memory controller, designed for
exceptionally high performance. Supporting DDR200/266/333/400 memory,
the VIA Apollo P4X400 provides lightning fast access to system memory and
can reach a peak bandwidth of 3.2GB/sec, 35% 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 P4X400 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 P4X400 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 P4X400 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 P4X400 the ultimate platform for
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.
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?? 8X V-Link: The VIA Apollo P4X400 is equipped with new 8X V-Link Chip
interconnect between North and South Bridge. 8X 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.
This white paper describes the features of the VIA Apollo P4X400 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 and DDR400: 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.
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
lowered heat dissipation, again increasing the effectiveness of DDR in mobile and
server applications.
These basic specifications of SDRAM technologies are summarised below.
Page 3VIA Apollo P4X400 Chipset White Paper
Clock Rate Effective Memory bandwidth Voltage
Clock Rate
PC100 100MHz 100MHz 0.8GB/sec 3.3
PC133 133MHz 133MHz 1.05GB/sec 3.3
DDR200 100MHz 200MHz 1.6GB/sec 2.5
DDR266 133MHz 266MHz 2.1GB/sec 2.5
DDR333 167MHz 333MHz 2.7GB/sec 2.5
DDR400 200MHz 400MHz 3.2GB/sec 2.5
DDR400 offers the greatest memory bandwidth yet, a 35% increase over DDR266,

VIA P4X400 是一款針對(duì)Intel Pentium 4 (P4)架構(gòu)主板的高性能芯片組解決方案。它由 VIA Technologies, Inc.（威盛）公司開(kāi)發(fā)，專(zhuān)為第四代（Pentium 4）處理器設(shè)計(jì)，提供對(duì)前端總線(xiàn)(Front Side Bus, FSB)最高可達(dá)1333MHz的支持，這使得它能夠有效提升系統(tǒng)的數(shù)據(jù)傳輸速度和整體性能。 該芯片組集成了南北橋功能，支持雙通道DDR內(nèi)存技術(shù)，可以實(shí)現(xiàn)高達(dá)2666 MT/s的工作頻率，顯著提高了系統(tǒng)在多任務(wù)處理、圖形渲染以及高帶寬應(yīng)用中的表現(xiàn)。此外，VIA P4X400還提供了豐富的擴(kuò)展插槽，包括PCI-E x16顯卡插槽用于連接高端圖形處理器，多個(gè)PCI/AGP/PCI-X插槽以滿(mǎn)足不同的外設(shè)需求，以及USB 2.0、千兆以太網(wǎng)接口等現(xiàn)代I/O標(biāo)準(zhǔn)，方便用戶(hù)連接各類(lèi)高速外部設(shè)備。 總體來(lái)說(shuō)，VIA P4X400憑借其出色的兼容性和性能優(yōu)化，在當(dāng)時(shí)是構(gòu)建高效能Pentium 4平臺(tái)的理想選擇，對(duì)于需要追求更高運(yùn)算能力和多媒體處理能力的計(jì)算機(jī)系統(tǒng)有著重要的作用。