Home > Articles > Hardware > Upgrading & Repairing

  • Print
  • + Share This
From the author of

AMD Athlon 64 X2

The AMD Athlon 64 X2, like its predecessors, is based on the AMD Opteron workstation and server processors. AMD introduced its dual-core Opteron processors on April 21, 2005, and officially introduced the Athlon 64 X2 dual-core processors on May 31, 2005.

Code-named "Toledo," the Athlon 64 X2 processor will initially be offered in four models: 4200+, 4400+, 4600+, and 4800+. These processors have the following features in common:

  • 128KB L1 cache per core
  • 1GHz HyperTransport interconnect
  • .09 micron (90nm) silicon-on-insulator production process
  • Supports "Cool and Quiet" (reduced clock speed and power consumption) when power profile is changed to Portable/Laptop and AMD's processor driver is installed
  • Supports NX (no execute) buffer overflow attack protection (Windows XP SP2)
  • Socket 939 form factor
  • Single die contains two processor cores

The Athlon 64 X2, unlike the Pentium D and Pentium Extreme Edition, contains a crossbar controller to connect each core to memory and I/O. This design enables the processor cores to communicate with each other without first transferring data outside the processor. Figure 2 illustrates the design.

Figure 2

Figure 2 The block diagram of the Athlon 64 X2 processor.

Table 3 compares the features of the first four Athlon 64 X2 processors.Table 3 – Athlon 64 X2 Processor Comparison






Actual Clock Speed





L2 Cache (per core)





Total L2 Cache size










As you can see from Table 3, the 4200+ and 4400+ have the same clock speeds, but differ in the amount of L2 cache per core. Similarly, the 4600+ and 4800+ also have the same clock speeds, but differ in the amount of L2 cache per core. As I have written in Upgrading and Repairing PCs, the size of L2 memory cache makes a significant difference in system performance, especially with memory-bound applications.

Moving to Athlon 64 X2

The Athlon 64 processor was designed from the beginning with dual-core capabilities in mind. Thus, only a BIOS upgrade is needed to enable a Socket 939 motherboard to function with an Athlon 64 X2 processor.

If you are responsible for managing a number of systems, this is an advantage over the Intel approach in several ways:

  • You will not need to purchase new systems or replace motherboards to upgrade to Athlon 64 X2 processors if you have existing Socket 939-based Athlon 64 systems
  • You do not need to alter existing software images you use for maintenance when you upgrade existing systems to Athlon 64 X2 processors
  • You can install Athlon 64 X2 processors in existing Socket 939 motherboards and use them immediately in single-core mode, even if BIOS upgrades are not immediately available

The ability to easily upgrade current systems helps to make up for the much higher initial cost of the Athlon 64 X2 processor compared to the Pentium D processor. For example, the Athlon 64 X2 4200+ has an estimated selling price over twice that of the Pentium D 2.8GHz ($537 versus $241).

  • + Share This
  • 🔖 Save To Your Account