HP XU800 - Manual (Page 36)

36
2 System Board
Memory Controller Hub (8240)
The following table shows the features that are available in the MCH Host
Bridge/Controller.
Feature Feature
• Processor/Host Bus:
❒ Supports up to two Pentium III processors at: 100 MHz/133
MHz Host Bus frequency.
❒ Supports full Symmetric Multiprocessor (SMP) Protocol for
up to two processors.
❒ Provides an 8-deep In-Order Queue supporting up to eight
outstanding transaction requests on the host bus.
❒ Desktop optimized GTL+ bus driver technology (gated GTL+
receivers for reduced power).
❒ Support for 36-bit host bus address.
❒ IERR and BERR signals generate SCi/SERR.
❒ Parity protection on address and resource signals:
Parity errors generate SERR.
• Accelerated Graphics Port (AGP) Interface:
❒ Single Universal AGP PRO connector.
❒ AGP Rev 2.0 compliant, including AGP 4x data transfers and
2x/4x Fast Write protocol.
❒ AGP Universal Connector support via dual mode buffers to al-
low AGP 2.0 3.3 V or 1.5 V signalling.
❒ AGP PIPE# or SBA initiated accesses to DRAM is not
snooped
❒ AGP FRAME initiated accesses to DRAM are snooped
(snooper identifies that data is coherent in cache memory).
❒ Hierarchical PCI configuration mechanism.
❒ Delayed transaction support for AGP-to-DRAM reads that
cannot be serviced immediately.
• Memory Controller.
Direct Rambus:
❒ Dual Direct Rambus Channels operating in lock-step (both
channels must be populated with a memory module).
Supporting 300 MHz or 400 MHz.
❒ RDRAM 64 Mb, 128 Mb, 256 Mb devices.
❒ Minimum upgrade increment of 16 MB using 64 Mb DRAM
technology.
❒ Up to 64 Direct Rambus devices (without using MRH-R).
Dual channel maximum memory array size is:
— 512 MB using 64 Mb DRAM technology.
— 1 GB using 128 Mb DRAM technology.
— 2 GB using 256 Mb DRAM technology.
❒ Up to 8 simultaneous open pages:
— 1 KByte page size support for 64 Mbit, 128 Mbit and 256
Mbit RDRAM devices.
— KByte page size support for 256 Mbit RDRAM devices.
SDRAM:
❒ Up to 8 GB of SDRAM using four external Memory Repeater
Hubs for SDRAM (MRH-S).
Currently, two MRH-S devices are supported.
❒ Interleaved 100 MHz support using 4 MRH-S for a maximum
bandwidth.
❒ Non-Interleaved 100 MHz support using 2 MRH-s for lower
cost and upgrade path.
❒ Unbuffered DIMMs are supported.
❒ Up to 4 rows or 2 DS DIMMs per MRH-S.
❒ Up to 8 simultaneous open pages:
— 2 KByte page size support for 64 Mbit SDRAM devices.
— 4 KByte - 16 KByte page sizes supporting 64 MBit to
256 Mbit SDRAM devices.
❒ Configurable optional ECC operation:
— ECC with single bit Error Correction and multiple bit Error
Detection.
— Single bit errors corrected and written back to memory
(scrubbing).
• Hub Link 8-bit Interface to ICH:
❒ High-speed interconnect between the MCH and ICH
(266 MB/sec).
• Hub Link 16-bit Interface to P64H:
❒ High-speed interconnect between the MCH and P64H
(533 MB/sec).