AMD Opteron microprocessor family

AMD Opteron is a family of server-class processors based on K8 architecture. Opteron family was introduced in April 22, 2003, before any other processors in AMD K8 family. All Opteron processors released at that time were socket 940 only and required motherboards with expensive registered RAM. The Opterons had single-channel DDR memory controller and three HyperTransport links. The processors also included AMD 64-bit technology, supported SSE and SSE2 instructions, and had large 1MB level 2 cache. First Opteron processors were manufactured using 0.13 micron technology - same technology was used for the latest K7 processors. Though the Opterons were running at lower frequencies than Athlon XP processors, their Thermal Design Power (TDP) was higher. TDP was slightly lowered with the introduction of 0.09 micron Opteron CPUs in 2005. These processors added support for SSE3 instructions and increased maximum frequency of HyperTransports links from 800 MHz to 1 GHz. Some uni-processor Opterons were also manufactured for socket 939. These microprocessors were essentially fast Athlon 64 processors - they could work with less expensive unbuffered RAM and had only one Hypertransport link.

All Opteron processors were manufactured in three different versions:

• Processors for uni-processor systems
• Processors for dual-processor systems
• Processors for systems supporting up to 8 processors

To distinguish between different Opteron versions AMD used Opteron model numbers. Each Opteron processor had three-digit model number. The first digit (1, 2 or 8) specifies processor scalability, i.e. how many processors can be used in one system. A number, formed from the second and third digits, is used to specify relative processor performance. This number is greater for faster Opteron processors, and it can be used to compare processors with different scalability. For example, Opteron 840 is slower than Opteron 142 when used in a single-processor system.