AMD 30925 manual Integrated DDR Dram Memory Controller, HyperTransport Technology

Builder’s Guide for AMD Opteron™ Processor-Based	30925 Rev. 3.04 February 2004
Servers and Workstations

Integrated DDR DRAM Memory Controller

The 128-bit wide integrated DDR DRAM memory controller:

•changes the way the processor accesses main memory, resulting in increased bandwidth, reduced memory latencies, and increased processor performance.

•allows available memory bandwidth to scale with the number of processors.

•can support up to eight registered DDR DIMMs per processor.

•has available memory bandwidth of up to 5.3 Gbytes/s (with PC2700) per processor.

HyperTransport™ Technology

The HyperTransport technology of the AMD64 architecture offers the following features:

•A scalable bandwidth interconnection between processors, I/O subsystems, and other chipsets

•Support for up to three coherent HyperTransport links, providing up to 19.2 Gbytes/s of peak bandwidth per processor

•Up to 6.4 Gbytes/s bandwidth per link providing sufficient bandwidth for supporting new interconnects including PCI-X, DDR, InfiniBand, and 10G Ethernet

•Low power consumption (1.2 W) to help reduce the system thermal budget

Other Features of the AMD Opteron™ Processor

Other features of the AMD Opteron processor include:

•64-bit wide key data and address paths that incorporate a 48-bit virtual address space and a 40-bit physical address space

•ECC (error correcting code) protection for L1 cache data, L2 cache data and tags, and DRAM with hardware scrubbing of all ECC-protected arrays

•Lower thermal output levels and improved frequency scaling through .13 micron SOI (silicon- on-insulator) process technology

•Support for all instructions necessary to be fully compatible with SSE2 technology

•Two additional pipeline stages (compared to AMD’s 32-bit architecture) for increased performance and frequency scalability

•Higher IPC (instructions-per-clock) achieved through additional key features, such as larger TLBs (translation lookaside buffer), flush filters, and enhanced branch prediction algorithms

10 AMD Opteron™ Processor Key Architectural Features Chapter 1