Now a month after AMD's dual core Opteron was officially launched last month, a number of hardware vendors have reacted by announcing products based on the new processors. Dell is not among them -- more later.

AMD is charging more for dual-core parts than for single core -- as you'd expect -- with a top of the line Opteron 800 dual costing $2,649 (1,000-off) against $1,514 single-core. AMD is not pitching them as dual-core, though, but is making more of the added performance they offer. This makes sense if you consider that the most important aspect of any processor is its real-world performance, not the number of cores.

In addition, AMD has to be careful not to imply that dual-core is too big a step-change or it might lose the marketing benefit of the pin-compatibility of the new products. The only way to tell the difference from the outside is that all dual-core model numbers end in 5.

Why go dual core? The big constraints on processor makers right now are power consumption and heat generation, which why ratcheting up the gigahertz is seen by neither Intel nor AMD as the way to greater performance. Instead, virtualisation and multiple cores are the two main trends.

In terms of who is selling finished product, stand up the usual suspects, IBM, HP and Sun. All have shown willingness to support AMD's decision to sell the to-end 800 series before the lower-end models, presumably because this allows them to benefit from the halo effect of selling high-spec blades workstations and four-way servers from the outset. And the three vendors all have some form of stake in the success of the dual-core Opteron.

Designed by company co-founder Andreas Bechtolsheim, Sun's new Opteron-based servers - codenamed Galaxy - are due for release by the end of 2005.

On the roadmap are two entry-level servers, a 1U (4.4 cm) dual-processor server with two PCI-X slots, two hard drives, and up to 16GB of RAM, and a larger 2U system that can contain the same amount of processors and memory, but will have four hard drives and five PCI-X slots. At the top end will be two 4U machines, one that will support four processors and as much as 32GB of memory and a second eight-way system with as much as 64GB of memory.

Sun will eventually be moving all its x64 products over to dual-core Opterons, kicking off with the Sun Fire V40z server which needs only a chip swap to become a dual-core device. Expect to see the results this month.

Bechtolsheim has said that Sun expects its new AMD systems to outperform Intel's Xeon products in both clusters of two-way servers and larger multi-processor servers. Galaxy will also include ultra-thin Opteron blade servers designed to fit into the same chassis as Sun's blade servers based on its SPARC processors, according to a Sun engineer's blog.

In addition to hardware issues, Sun signed a strategic agreement with AMD in 2003 to deepen their relationship by building what Sun systems executive Neil Knox called a collaboration "on the creation of an AMD 64 or Opteron software ecosystem." However, Sun's enthusiasm may be alloyed by its need to continue to sell its own high end system based on its SPARC chip.

IBM also has a problem with an in-house processor architecture, in this case, the Power 5. However, Big Blue is happy to divide up its server lines along architecture lines, with its eServer products housing Opterons, while the higher-specified mid-range machines are mainly Power-based products.

In terms of new Opteron-based machines, IBM is now selling and is close to shipping the eServer 326, a 1U rack-mounted server with dual-core chips. And it has a stake in AMD's success, as it collaborated with AMD to develop silicon-on-insulator technology, whose benefits include Opteron's lower power consumption.

Now with a new leader, HP is keen to keep Dell at bay. Dell of course is famously Intel-only -- see below. Meanwhile, it can use dual-core performance to pre-empt Dell in the performance stakes, as AMD got there first.

HP claims that it's first to supply such machines and that it provides an easy path to 64-bit computing. So you can anticipate that the architecture will trickle down to the Opteron 200-based products such as the ProLiant BL25p, BL35p, DL385 this month.

Meanwhile, HP is trumpeting its new dual-core Opteron-based ProLiant DL585 rack-mounted and BL45p blade servers as "revolutionary machines [that] offer eight processor cores at four-processor prices".

HP's commitment is greater than either of its two rivals, as its range of Opteron-based systems include two and four-way servers as well as workstations, by far the widest range of any of the hardware OEMs.

There's no story here as Dell remains resolutely Intel-only. However, there will come a time when Dell will have to move upmarket if it's to expand the scope of its operations beyond the low-end. And that may well mean embracing an AMD architecture because for customers who need more and are prepared to pay for it, it makes no sense to ignore the sweet spot if AMD is delivering first, as it has done. But so far, Dell has ignored the siren calls.

AMD's dual-core Opteron has made a considerable impact -- and it remains to be seen how the market will react.