AMD today launches nine versions of its long-awaited quad-core processor, codenamed Barcelona, clocking up 2GHz.

The company says the processor, described as the most advanced x86 design to date, can be used as a slot-in replacement for dual-core Opterons with equivalent thermal characteristics and power consumption – boosting the processing power by up to 79 percent.

The new processors are all designed for demanding tasks in data centres but the technology will migrate to desktop Phenom processors as soon as this December, AMD chief executive Hector Ruiz is expected to say during a webcast this afternoon.

The company says there have been significant enhancements to the processor cores, in addition to putting four of them on a single die. Each core has 512Kbyte of Level 2 cache memory, in addition to 2Mbyte of shared cache.

AMD claims their performance is best in class using benchmarks relevant to the tasks for which they are designed. They are true quad-cores, tightly integrated, rather being two dual-cores on a single die like the latest Intel quad-cores. But Intel's processors clock up to 3GHz.

However AMD is laying great emphasis on power efficiency – performance per watt, which has become a very big issue in data centres. The company has cited a new metric for this which is says offers a truer reflection of the running costs and power requirements.

The usual metric is the Thermal Design Power (TDP), the maximum theoretical consumption if the processor is run flat out. This, as the name suggests, is needed to indicate the "thermal envelope" of the systems it will fit into – that is, the maximum heat they are designed to dissipate.

AMD, which accepting the need for TDP ratings, also cites the average CPU power (ACP) – the power drawn while using "relevant, commercially useful high-utilisation workloads."

All the new quad-cores are 65nm scale using strained-silicon. They support DDR2 memory clocking up to 667MHz and use the 1207-pin Socket F. Five have the suffix HE, for high efficiency, which means they have and ACP of 55watts; the rest have an ACP of 75watts.

They are (core frequency and bulk price in brackets): 8350 (2GHz, £1019); 8347 (1.9GHz, $786); 8347HE (1.9GHz, $873); 8346HE (1.8GHz, $698); 2350 (2.0GHz, $389); 2347 (1.9GHz, $316); 2347HE (1.9GHz, $377); 2346HE (1.8GHz, $255); 2344HE (1.7GHz, $209).

Confusion of the AMD generation ... see Test Bed.