AMD is picking up the pace for its six-core, Istanbul family of Opteron processors, saying it will ship the chips to paying customers in May with server OEM partners shipping in June. That brings the Istanbul chips ahead by several months and gives AMD a chance to leapfrog Intel in the two-socket server space, where Intel has …
Amdahl's law has been telling us for over 4 decades that throwing more cores at a problem quickly reaches the point of diminishing returns. For the last decade or so the workloads and CPUs dictate that more than about 6 cores doesn't buy much if anything in extra performance. For the average PC, most users won't ever see any improvement with more than 6 cores so I expect that to remain the high performance sweet spot for years to come.
@Tim, Re: For the average PC
These are big, expensive, multi-socket processors. They are most definitely not aimed at the average PC, and I rather suspect they are not aimed at runnig a single multithreaded task. This sort of box would be ideally suited to be a virtual server host, for example. There isn't really a situation where you can have too many cores and too much IO bandwidth for that sort of system.
That said, software bloats to consume available resources. I have no doubt that in the near future we'll see desktop applications which take full advantage of a 64bit operating system's vast address space, and require half a dozen cores with a gig or two of ram apiece in order to run smoothly. I expect they'll do useful things like let you write documents and add up columns of figures.
The four processor diminishing return is for shared bus, the Transputer 'research' showed that by having direct links between processors (instead) you can break this trend.
These are server processors, shared between many user tasks.
Your PC already have lots of processors, apart from the main CPU: keyboard processor, graphic pipeline processors, disk drive processors, printer processor, audio processor
re: re: n=6?
ISTR that round here recently there was a report on some research showing that there are indeed diminishing returns on multi-core CPUs* as the core count increases. They'd come up with 8 as a limit beyond which handling core contention for resources starts to consume a significant amount of the grunt that the extra core(s) are there to provide.
I guess the 12-way Magny-Cours is AMD's way of sitting with their fingers in their ears and going "La, la, la, we're not listening" to that one.
*There's a world of difference between multiple CPUs (with their own RAM, cache, IO channels and such) and multicore CPUs (with their unfortunate limitations in these areas).
TeeCee: the cores will have their own RAM
I'm pretty sure that, even with existing AMD multi-core processors, there's more than one group of cores, each with their own dedicated memory interconnects and RAM. AMD seems to quite like this sort of design. It appears likely that each chip in the Magny-Cours package will have its own set of memory interconnects, just like if it was two 6-core processors.