AMD64 technology enables leading-edge software performance and new experiences & capabilities. Specifically, AMD64 technology:

Provides the highest performance levels without any changes to existing 32-bit applications.
Allows simultaneous, high-performance 32-bit and 64-bit computing, offering end users an easy, compelling and affordable means to take advantage of tomorrow’s emerging applications.

Doubles the number of internal registers enabling increased performance
Vastly expands memory addressability well beyond 4GB for breathtaking realism in graphic intensive applications like 3D games, and real-time results for large memory footprint applications like digital

Enhanced Virus Protection for Windows® XP SP2
Enhanced Virus Protection enabled by Windows XP SP2 is designed to prevent the spread of certain viruses, like MSBlaster and Slammer, significantly reducing the cost and down-time associated with similar viruses and improving the protection of computers and personal information against certain PC viruses.*

HyperTransport™ technology
HyperTransport technology helps increase overall system performance by reducing traditional system bottlenecks, increasing system I/O bandwidth, and reducing I/O latency; which translates into overall better performance, quicker loading of applications and extraordinary multimedia experiences.

The integrated Double Data Rate (DDR) memory controller dramatically reduces one of the worst, and most-often encountered system bottlenecks found in existing platform designs; that is memory latency. The integrated DDR memory controller found in the AMD Athlon™ 64 FX processor:

Provides a performance boost by directly connecting the processor to the memory, thus dramatically reducing memory latency. As a result, performance is greatly improved on many applications, especially memory intensive applications like digital media and 3D games.

Supports industry-standard, widely-available DDR memory modules for high-performance systems to reduce total cost of ownership and/or development.

Features ECC protection that enables increased system reliability, helping to ensure your systems run smoothly.

High-Performance, On-Die Cache
The AMD Athlon 64 FX processor features a large high-performance, on-die cache memory system for desktop PCs. The 1152KB (128KB L1 + 1024KB L2) of total usable cache improves instruction throughput. The end result is greatly improved performance on many applications, especially large memory workloads like digital media applications.
3DNow!™ Professional Technology + SSE2 Instructions

With the addition of SSE2 instructions to existing 3DNow!™ Professional technology, the AMD Athlon 64 FX processor is compatible with the largest installed base of multimedia-enhanced software.

Software specifically tuned for this suite of instructions means smooth, rich, lifelike images, precise digital audio and an enriched Web experience.