of VIA P4X266A
Enhanced Processor Bus
The VIA Apollo P4X266A features an enhanced processor bus interface
that more efficiently takes advantage of the quad pumped bus of the
Intel® Pentium® 4 processor. Now, up to 12 instructions can be queued
in the processor bus interface, allowing the high speed 400MHz bus
of current and Pentium® 4 processors to run at optimal efficiency.
This also reduces latency between the processor and other peripherals
and devices, which improves overall system operation. The VIA Apollo
P4X266A also offers support for high bus speeds, allowing seamless
upgradeability to possible future processors.
Performance Driven Design
Using the highly efficient memory controller of the renowned VIA
Apollo KT266A, the VIA Apollo P4X266A offers exceptionally high memory
performance. This is accomplished through improved timings and deepened
queues. Supporting up to 4GB of DDR200 or DDR266 memory, the VIA
Apollo P4X266A provides lightning fast access to system memory. Moreover,
the VIA Apollo P4X266A offers a highly developed AGP4X interface,
ensuring the highest possible graphics performance with a myriad
of AGP4X graphics accelerators.
The VIA Apollo P4X266A is part of the family of VIA Modular Architecture
Platforms (V-MAP). As a modular solution, the North and South Bridge
of VIA Apollo P4X266A are completely pin compatible with current
and future products. The VT8753A North Bridge of P4X266A is pin compatible
with the VT8753 of P4X266, and the VT8751 of P4M266. Additionally,
VT8753A can interface with three separate pin-compatible South Bridges:
The VT8233 offering VIA Ethernet MAC, the VT8233C featuring 3Com
Ethernet MAC, and the VT8233A supporting the new ATA/133 drive standard.
With this wide range of pin-compatible products, up to six distinct
chipsets are possible for Intel® Pentium® 4 processors while using
the same motherboard design.
High-Speed V-Link Hub Architecture
The VIA Apollo P4X266A takes advantage of VIA's high performance
V-Link Hub Architecture, which provides a dedicated 266MB/s bus between
the North and South Bridge. Less advanced chipsets use the 132MB/s
PCI bus as a link, which must be shared with all PCI peripherals.
V-Link greatly improves data transfer rates when high-speed interconnect
technologies such as USB2.0, IEEE1394, and ATA/133 are implemented
in a single system.
VPX-64 64bit/66MHz PCI Controller
The VPX-64 64bit PCI Controller (model number VT8101) is a companion
chip that allows existing VIA chipsets to support high-bandwidth
64bit PCI in both 33MHz and 66MHz modes. VPX-64 enables VIA Apollo
chipsets to offer up to 533MB/s of PCI bandwidth for high end peripherals
like Gigabit Ethernet, Fibre Channel and Ultra SCSI/320 and is perfect
for implementation in server systems based on the VIA Apollo P4X266A.
VPX-64 also supports up to six traditional 32bit/33MHz PCI devices,
allowing VPX-64 equipped system designs to support no less than 10
PCI devices, and up to 12 in total. VPX-64 is available in a 27x27mm,
265 pin PGA package. VPX-64 interfaces directly to the dual mode
AGP/XIP port present in existing V-MAP compatible chipsets.