The AMD Opteron is the first eighth-generation x86 processor (K8 core), and the first of AMD's AMD64 (x86-64) processors, released April 22, 2003. It is intended to compete in the server market, particularly in the same segment as the Intel Xeon processor.

The TOP500 list currently ranks an Opteron-powered machine at the Dawning 4000A project in China as the tenth fastest supercomputer in the world.

Technical description

The Opteron's main advantage is the ability to run existing 32-bit applications without speed penalties, as well as the 64-bit applications that can directly access more than 4 Gb of RAM (the physical limit of a 32-bit system).

The processor has an integrated DDR SDRAM memory controller, avoiding the need for a northbridge and reducing the latency penalty for accessing the main RAM. Although the memory controller may be supplanted by an external chip as new memory technologies enter the market, one will then lose the benefits of an in-core controller (thus necessitating the release of new processors with updated memory controllers to match the speed of new memory technologies). Also, because each Opteron has its own memory controller and bank of memory, Opteron servers scale better than Xeon servers across CPUs. Whereas Xeons have to share a diminishing memory bandwidth as the number of processors increases, Opterons have no such drawback as memory bandwidth increases with each CPU added.

In multi-processor systems (more than one Opteron on a single motherboard), the CPUs communicate using the Direct Connect Architecture over high-speed HyperTransport links. Each CPU can access the main memory of another processor, transparent to the programmer.

Models

Each chip has a three-digit model number, in the form "Opteron xyy". The first digit (the x) specifies the number of CPUs on the target machine:

• 1 - Designed for uniprocessor systems
• 2 - Designed for dual-processor systems
• 8 - Designed for systems with 4 or 8 processors

The last two digits in the model number (the yy) give an indication of the speed of the CPU.

Opteron (130 nm SOI)

• SledgeHammer (1yy, 2yy, 8yy)
• CPU-Steppings: B3, C0, CG
• L1-Cache: 64 + 64 KB (Data + Instructions)
• L2-Cache: 1024 KB, fullspeed
• MMX, Extended 3DNow!, SSE, SSE2, AMD64
• Socket 940, 800 MHz HyperTransport
• Registered DDR-SDRAM required, ECC possible
• VCore: 1.50V - 1.55V
• First Release: September 23, 2003
• Clockrate: 1400 - 2400 MHz (x40 - x50)

Opteron (90 nm SOI)

• Venus (1yy), Troy (2yy), Athens (8yy)
• CPU-Steppings: E4
• L1-Cache: 64 + 64 KB (Data + Instructions)
• L2-Cache: 1024 KB, fullspeed
• MMX, Extended 3DNow!, SSE, SSE2, SSE3, AMD64
• Socket 940, 1000 MHz HyperTransport
• Registered DDR-SDRAM required, ECC possible
• VCore: 1.35V - 1.4V
• Enhanced Virus Protection (NX Bit)
• Optimized Power Management (OPM)
• First Release: February 14, 2005
• Clockrate: 1600 - 2600 MHz (x42 - x52)

See also

• List of AMD Opteron microprocessors

External links

• AMD Technical Docs
• AMD's home page
• NerdyPC
• AMD Opteron article
• AMD Opteron reviews
• AMD Opteron Socket 940 motherboards