The x86 stages a cutting-edge comeback

Your basic x86 server doesn't look so average any more. In fact, with 64-bit extensions on the table and multi-core processors in...

Your basic x86 server doesn't look so average any more. In fact, with 64-bit extensions on the table and multi-core processors in the works, the venerable PC server is looking downright jazzy.

The x86 rebirth buzz began when AMD and Intel added 64-bit support to their processors. The 64-bit extensions show up in AMD's Opteron and Intel's Xeon chips. But the buzz grows a lot louder when you throw in the multi-core angle.

A multi-core processor gives you two processors on one chip. IBM, for example, offers the dual-core Power5 processor, while Sun has released a dual-core UltraSparc chip. PC suppliers are not to be outdone: AMD is developing multi-core processors for servers and high-end workstations, and Intel plans to ship dual-core processors for its server and desktop systems. Both company products are expected in late 2005.

The core issue

Although it will be years before multi-core designs become pervasive, the fact that they usually run at lower frequencies that burn less power than the latest single-core processors will eventually make data centre servers denser than today's single-core systems, says Tom Halfhill, senior analyst with Microprocessor Report.

"The whole idea of having two cores on one chip is that they are more efficient. For the same amount of data centre square footage, you can have more processing power crammed in," he says.

But dual-core processors will only achieve mainstream acceptance when suppliers resolve the thorny issue of software licensing. As far as applications or the computer's operating systems are concerned, a dual-core processor looks like a two-processor system. But should it be licensed as such? Not according to Scott Wolfe, IT enterprise architect with Boeing Employees Credit Union.

"We license Oracle per processor, so now when we do dual cores, is that two processors?" he asks. "That dual-core processor is not as powerful as two single processors, so now we're paying essentially twice the licensing for less than twice the computer power."

Most suppliers, including Microsoft and Novell, have not disclosed how they expect to treat multi-core processor licences. Those suppliers that have already decided on this issue have taken different stances. A dual-core processor will be licensed as two separate chips as far as Oracle is concerned, but the same processor will require only one licence from Red Hat.

While PC software suppliers have some time to decide how they'll handle licensing, IDC research director Al Gillen expects most will follow Oracle and license multi-core systems as multiprocessor machines.

Perhaps the new systems will spur software suppliers to reconsider their processor-based pricing models. That's the hope of Dave Gallaher, director of IT development for Jefferson County in Colorado.

"At some point, I would have to call it the equivalent of counting the lug nuts on a car and using that as the basis of what you pay for the car," he says. He thinks software suppliers should move from this model and focus instead on one question in particular: what's the value of the product?

Nothing to lose

With their 64-bit x86 extensions, AMD and Intel have created processors that are 64-bit-capable but can also run all today's 32-bit PC software out of the box. Because the 64-bit extensions, called AMD64 by AMD and Extended Memory 64 Technology by Intel, do not slow 32-bit software performance, customers have nothing to lose by adopting the new processors.

Intel and AMD intend to make their 64-bit instructions a standard part of their PC processors. Both companies say the 64-bit extensions will be compatible with each other's products and with 32-bit x86 chips.

This means that most PC server systems will soon be 64-bit-enabled, according to Stuart McRae, manager of IBM's xSeries servers. "In the first quarter of next year, virtually everything we ship will be 64-bit-enabled," he says.

Gillen agrees. "By this time next year, you'll be hard-pressed to find a 32-bit system."

Still, the 64-bit software that will run on these chips is only beginning to emerge. Microsoft recently pushed back the release of a production version of Windows for 64-bit extensions until 2005, and suppliers see no point in delivering Windows applications before the operating system is ready.

For Linux users, 64-bit operating system support is already available from Red Hat and Novell's SuSE Linux. But even on Linux, application support is still in the early stages - mainly confined to open-source products such as PostgreSQL and MySQL, and to high-performance computing applications.

Risc reduction

The advent of 64-bit x86 processors will go a long way toward eroding a primary advantage of 64-bit Risc systems based on chips such as Sun's UltraSparc and IBM's Power processor.

Because 64-bit applications can process numbers with twice as many binary digits as their 32-bit counterparts, they can address a larger range of system memory. A 32-bit system can't address more than four gigabytes of memory at a time; with 64-bit systems, this limit theoretically jumps to 16 billion gigabytes.

McRae says that the maximum amount of addressable memory supported by IBM's 64-bit Xeon systems today is 16Gbytes - far less than the theoretical maximum, but still four times that of 32-bit systems.

While this change might not have any impact on an application like Microsoft Word, it will have a big effect on any application that needs to store large amounts of data in memory. Databases, e-mail servers, collaboration software and even access software such as Citrix Systems' MetaFrame will benefit from the move to 64 bits, McRae says.

"Customers need to think about which applications are memory-intensive and which ones can get the most bang for the buck by moving to a 64-bit operating system. They're going to get the hardware functionality whether they want it or not," he says.

Gallaher reckons it spells the final end for Unix. "Why would you really want to buy a big Unix box when you can have a big Linux box?"

Jefferson County already has switched much of its IT operations from HP-UX to Linux, and the county is now in the process of evaluating 64-bit systems based on Intel and AMD PC processors. Gallaher says the county currently has 10 PA-Risc servers and will phase out two of them over the next six months.

However, where the switch to Linux has really had an impact is in the new applications the county has added over the past few years. "We have not written an application to run on HP-UX in years," says Gallaher. During that same time, the number of Linux machines at Jefferson County has gone from zero to 70.

For the $3,000 to $5,000 the county would spend on a 64-bit PC server, Gallaher says he would get comparable performance from a Risc system that costs 10 times as much. Long live the PC processor.

Robert McMillan writes for IDG News Service

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