Multicore Mania

Continued from page 1

Programmers have already built multithreading into Windows XP, Linux, and the Mac OS X operating systems, so they can throw the power of one CPU at system background tasks and the other CPU at, for instance, a demanding application such as displaying video. On the other hand, many application vendors, including game makers, haven’t revised their applications yet.

“We have multi-threaded software in scalable server applications today, but it is rarer in client applications” for desktop computers, Krewell says. “Adobe has embraced multithreading for content creation software, including Adobe Photoshop; but most other application software companies haven't done so yet.”

Also, this first round of chips -- including AMD’s Athlon 64 X2 Dual-Core and Intel's Pentium D -- still produce more heat than designers would like. That forces the dual cores to ratchet themselves down at times and run at less than their potential top clock speeds. So, in fact, gamers and other users of high-intensity applications are often wise to use a PC based on a powerful single-core chip like AMD’s Athlon 64 FX.

A larger wave of multithreaded applications will arrive when Microsoft’s Windows Vista operating system ships in fall 2006, IDC's Rau says.

Just as importantly, the next generation of Intel dual-core chips will draw less power -- keeping their cool without compromise. Code-named “Conroe” for desktops, “Merom” for notebooks, and “Woodcrest” for servers, these chips should also debut in fall 2006.

Eight is Enough?

Multicore designs will be the dominant microprocessor trend for this decade and beyond, according to both Intel and AMD. By 2007, both companies plan to offer quad-core microprocessors for consumer desktop PCs. And Intel could introduce eight-core chips as soon as 2008, some analysts predict.

“You have to time the introduction of the hardware with the software,” says Phil Hester, AMD’s chief technology officer. “Going to two cores is a pretty good answer for many apps today.”

As AMD plans its future chips, including quad-core, it must balance chip production costs and software benefits. For instance, a chip with three cores and a large amount of cache memory may deliver more bang for the buck than a four-core chip, Hester says. That’s because many applications, including demanding ones like Adobe Photoshop, make use of cache memory to speed up tasks. "It may make more sense for us to spend on fewer cores and include more cache,” Hester says.

Another possibility that might give users of multicore machines a big performance payback is specialized cores designed to excel at certain tasks, say, graphics, Web browsing, or security tasks. “You might have one core running your XML stream while another does the standard PC work,” Hester says, mentioning that AMD is investigating this kind of design.

Fitting more cores into a microprocessor, however, is just the start of the design challenges that hardware and software companies will face in the era of multithreading. The fastest processor in the world will still wait around if a system’s main memory can’t keep pace with it. And this problem will grow if a chip has hundreds of cores.

Coming tomorrow: We take a closer look at the hardware and software challenges with multiple cores. What hurdles must be overcome before multicore processing can deliver on its promise?

Laurianne McLaughlin is a technology writer based in the Boston area.