Builder’s Guide for AMD Athlon™ 64 Processor-Based
Desktops and Workstations
31684 Rev.
3.00 September
2004
1.2
Integrated DDR DRAM Memory Controller
The 64-/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 and
−
can support up to eight registered DDR DIMMs with an AMD Athlon 64 FX processor.
−
can support up to four unbuffered DDR DIMMs with an AMD Athlon 64 939-pin
processor.
•
has available memory bandwidth of up to 6.4 Gbytes/s (with PC3200).
1.3
HyperTransport™ Technology
The HyperTransport technology of the AMD64 architecture offers the following features.
•
A scalable bandwidth interconnection between I/O subsystems and other chipsets
•
Up to 8.0 Gbytes/s bandwidth 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
1.4
Other Features of the AMD Athlon™ 64 Processor
Other features of the AMD Athlon 64 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.
•
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 Athlon™ 64 Processor Key Architectural Features
Chapter 1
