Thread your way through the dual-core maze

Intel has projected that by the end of 2006 more than 70% of desktop and mobile Pentium processors and 85% of server processors shipped will be dual-core.

Intel has projected that by the end of 2006 more than 70% of desktop and mobile Pentium processors and 85% of server processors shipped will be dual-core.

Dual-core and multicore processing, combined with hyper-threading, works by allowing one processor core to function as two or more "logical" cores. This boosts the amount of work a processor can do in the same time as a processor with a single core.

Analyst firm Gartner said dual-core x86 systems will offer  price/performance benefits. How large these will be is difficult to say until Intel introduces its fully-fledged dual-core processors (code-named Dempsey), which will include technology to make the two cores work together more efficiently.

Another attraction of dual-core and multicore x86 systems is that they allow users to get higher levels of scalability without having to pay extra for an expensively designed symmetric multiprocessor system, said Ian Brown, research vice-president at Gartner.

PC makers such as Dell recently began to sell systems based on the Intel Xeon MP, saying the multicore platform could at least double the performance of existing dual-processor 64-bit servers running certain optimised software applications.

However, for software to make use of this feature, it has to be rewritten in a way that allows portions of the application to run independently of one another.

Commercial applications that make use of dual-core processors' multithreading capabilities - termed hyperthreading by Intel - may be lacking when the processors arrive in volume.

"Although Intel's 2002 hyperthreading technology and related developer and application enabling programs and services have led to mainstream operating systems and hundreds of multithreaded applications, there continues to be much work left to do," said Intel.

Cengiz Oztelcan, Intel's Xeon platform marketing manager EMEA, said many computer-aided design and animation applications are ready to take advantage of dual-core. But he added, "We do not have figures of how many independent software suppliers have multithreaded their applications.

"If the application is not multithreaded it is not going to make use of dual-core."

Intel is dedicating "thousands" of software architects, programmes and services, and developer tools such as threading tools, analysers and binaries to help software suppliers develop threaded code.

Martin Hingley, vice-president of the European systems group at analyst firm IDC, said the big software suppliers such as SAP and Oracle are likely to be preparing their applications to take advantage of dual and multicore processors from both Intel and AMD.

"They understand multithreading and multicore because they have been writing their applications to work with Alpha and Power PC processors, and are therefore likely to find the move to multicore Intel and AMD chips fairly straightforward," said Hingley. 

"The difficulty is that the mass of software companies are not going to rewrite or recompile their applications. The mass of the applications out there have never shifted from being single-core and single-threaded."

A Microsoft spokesman said it was too early to talk about Microsoft's support for dual-core and multicore chips, although the company does have plans to enhance both the tools and operating system.

"With Visual Studio 2005 still fresh and Windows Vista not even out yet, we are a bit premature to be talking about those today," he said.

However, Microsoft said, "By default, Windows treats multicore chips as very efficient multprocessor systems, and will offload background tasks such as indexing, virus scanning and searching to other processors to help boost performance. And Visual Studio 2005 includes features to ease multicore programming, such as support for OpenMP and enhanced debugging support."

Meanwhile, the open source community has the opportunity to offer a robust alternative to Microsoft on dual-core chips, according to Gartner.

Brown said, "The leading Unix operating systems have very effective thread handling which generally means they scale well on multithreaded workloads and handle mixed workloads effectively. Linux is improving in its thread handling and more improvements are on the way, but it does not match the leading Unixes yet."

Analysts said most enterprise middleware platforms, J2EE application servers and database software is already multithreaded to take advantage of Risc-based servers based on dual-core processors, such as Sun's Ultrasparc IV, IBM Power, and HP PA-Risc.

Analysts said one issue that would continue to hold back the adoption of dual-core systems is software licensing, with some suppliers choosing to charge per processor, and others charging users for each processor core.

"The software licensing issue is going to become a real mess. All the server suppliers are having to keep a single-core version of their applications so people will not have to pay two licences," said Hingley. 

Nevertheless, analysts seem to agree that users will get better value from dual-core and multicore processor-based servers.

Is it worth moving to dual-core?

Business users should think before moving to dual-core processor platforms, according to analyst firm Gartner. Companies should make their decision based on the applications they use, and issues such as software licensing costs.

Ian Brown, research vice-president at Gartner, said if users have a performance-hungry application, or an application that is growing fast, then the extra headroom offered by dual-core may be useful.

However, there are other ways to increase performance. Systems that have 64-bit processing may offer a more useful performance boost for database software, for example, than sticking with 32-bit and going to dual-core, Brown said.

"If your application does not need strong processor performance - say it is file-and-print, web serving or some other infrastructure application - then you needn't feel obliged to invest in dual-core while there is still a premium for it.

"By the end of 2006, most x86 servers will have dual-core processors, so the price premium will be going away," he said.

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