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