TWO FOR THE PRICE OF ONE
========================================================
TEST CENTER REPORT InfoWorld.com
========================================================
Monday, September 10, 2001
- - - - - - - - - - - - - - - - - - - - - - - - - - - -
TWO FOR THE PRICE OF ONE
Posted September 7, 2001 01:01 PM Pacific Time
THERE ARE MANY WAYS to tally the cost of computer
hardware. During the lifetime of a PC server or
workstation, the machine consumes capital in
acquisition, support, maintenance, upgrades, and
operation (power and cooling). The ideal system
balances performance with low initial and continuing costs.
The best balance between power and value will be struck
by systems built using the latest dual-processor PC
platforms. New technology has brought new choices and
competition to the dual-CPU system market, driving
prices down while maintaining crucial operating system
and application compatibility. After working with
three new platforms offered by Intel and AMD, those of
us in the InfoWorld Test Center are left wondering why
anyone would buy a PC server or workstation with only
one processor.
But despite our enthusiasm for these new machines, we
still see some drawbacks. The AMD Athlon MP, Intel
Tualatin, and Intel Xeon platforms are far from
interchangeable; each uses unique components. Nor can
any of these new CPUs be used to upgrade existing PC
servers or workstations. Buying into one of these
dual-CPU platforms means buying entirely new PCs and
investing in upgrade and repair parts that are
incompatible with currently deployed PCs.
Nevertheless, we think they're worth the investment,
especially now that component prices are irresistibly
low. Thanks to low demand and cutthroat competition
between AMD and Intel, you can buy dual-processor
systems for what you would have spent on single-CPU
systems just a year ago.
Does every application benefit from multiple CPUs?
Certainly not. Not every PC user needs a workstation
and not every server is CPU bound (spending more time
computing than moving data around). But every company
has a core of demanding PC users who waste time
waiting for their computers to finish a job, be it
compiling source code, rendering a 3-D image, editing
a digital video, or performing any gating task that
must be completed before the user can move on. For
these users, and for servers generating dynamic or
secure content, a second CPU is like a spare PC within
a PC. Dual-processor machines can't quite do twice as
much work in the same amount of time, but the
performance gain is substantial enough to justify the
additional expense.
We tested the latest dual-processor platforms using
systems that, to varying degrees, we constructed
ourselves. Building our own generic systems gave us
two advantages: We didn't have to wait until Compaq or
Dell started shipping Tualatin, Xeon, or Athlon MP
hardware before we could test the platforms; and our
findings wouldn't be skewed by a single vendor's
proprietary spin on the technology. Because our tests
were performed on components, and not on commercially
available products, they do not constitute formal
reviews. We performed them in an attempt to tease out
essential differences among the platforms.
For the testing, we tried to create as level a playing
field as possible. We installed 1GB of RAM on each
system, performed a clean install of Windows 2000
Professional with Service Pack 2, and used BAPCo
Sysmark 2000, SPECint2000, and SPECfp2000 benchmark
software to gauge performance. BAPCo (Business
Applications Performance Corporation) Sysmark 2001
measures system performance by simulating the usage of
real applications such as Adobe Photoshop and
Microsoft Word, whereas SPECint2000 and SPECfp2000
measure compute-intensive integer and floating point
performance, respectively.
Note that we adapted the SPEC (Standard Performance
Evaluation Corporation) tests to make them more
applicable to dual-processor systems. Specifically, we
ran three parallel copies of each benchmark to ensure
that both CPUs remained burdened until the end of each
test. The charted results show the sum of the three
test processes. Our approach isn't sanctioned by SPEC
and our results shouldn't be compared with those of
other SPEC runs.
The benchmarks revealed some performance differences
among the platforms (see charts). Intel's Xeon led in
floating point performance, but fell short in integer
performance. For Intel's Tualatin, the reverse was
true. AMD's Athlon MP took second in the SPEC integer
and floating point tests, but proved slightly faster
overall in the BAPCo application simulation tests.
The most significant difference among these platforms
is cost The costs of two CPUs and 1GB of matching
memory run just $562 for Athlon MP, compared to $718
for Tualatin, and $1,075 for Xeon. When it comes to
balancing price and performance, Athlon MP is the
clear winner.
Intel Xeon
Intel's new Xeon processor shares its name with
technology that dates back to the Pentium II. All
Xeons -- new and old -- are built especially for
multiprocessor systems. The new Xeon uses Pentium 4
technology, but it is not compatible or
interchangeable with the Pentium 4. Xeon also requires
a special power supply, a fact we stumbled upon while
building our system.
The Supermicro P4DC6 motherboard we used for testing
comes with massive heat sinks to draw the heat away
from the Xeon CPUs. Power management circuitry keeps
Xeon cool under less trying workloads, but when
subjected to the stress of our benchmarks, the dual
1.4 GHz Xeons pumped out as much heat as a hair dryer.
Previous Xeon models benefited from large, fast cache
memories, but the new Xeon does not; its 256 KB cache
is the same size as that in the desktop Pentium 4.
Xeon's performance in our benchmarks, although
respectable, would have been boosted by a larger
cache. In all, Xeon's performance, weighed against
Tualatin's lower power draw and Athlon MP's lower
acquisition cost, make Xeon our third choice in this roundup.
Xeon carries the highest acquisition and upgrade costs
because of its use of expensive Rambus memory. For
example, memory vendor memman.com charges
approximately twice as much for Rambus as for its next
most expensive RAM. Rambus is much, much faster than
other types of memory, but the small gain in
application performance doesn't justify paying Rambus'
higher cost or risking abandonment when Intel moves to
DDR (double data rate) memory, the type of RAM used in
Athlon systems.
Xeon's lead in some of our benchmarks is probably due
to its higher clock speed (1.4GHz compared to 1.2GHz
for Athlon and Tualatin) rather than the superiority
of Rambus. If Intel lowers the price of Xeon, it'll
make a cost-effective workstation chip. But we're most
interested in seeing what the next generation of
large-cache Xeons, paired with affordable DDR memory,
can do for servers, especially larger machines with
four, eight, or more CPUs.
Intel Tualatin
The surprise entry in this contest is an Intel Pentium
III chip bred especially for low power consumption.
This cool-running CPU, code-named Tualatin, grabbed
our attention for being the only chip that wasn't
topped by a gargantuan heat sink and fan. Tualatin's
benchmark performance also surprised us. We like this
processor for two roles: the desktop, where low power
means low operating costs and quiet running; and the
clustered server, where you might rack up as many
dual-processor Tualatin servers as needed to do the job.
Our Tualatin review unit was a Supermicro 6011L, a
sleek 1U-high (1-3/4 inch) rack-mountable number with
dual removable Ultra160 SCSI drive trays. It cost only
$100 to equip the 6011L with a gigabyte of Registered
PC133 RAM. If Intel dropped the price on Tualatin it
could make a lot of trouble for AMD. As it is, we hope
that Tualatin starts a trend toward fast, low-power CPUs.
AMD Athlon MP
AMD has been manufacturing Intel-compatible CPUs for
many years, primarily targeting the low end of the
market with affordable alternatives to Intel
processors. Athlon MP is AMD's first dual processor
architecture, and its first showing is impressive. We
tested two Athlon systems, one workstation and one
server, both based on Tyan's Thunder K7 motherboard.
The combination of low cost and excellent performance
make Athlon MP our first choice, but AMD will have to
fight to keep that slot. Intel has aggressive plans
for faster CPUs, with the heady 2GHz barrier slated to
fall within a few months.
At just $324 per pair, the 1.2GHz Athlon MP CPU is the
least expensive in our roundup. Registered DDR memory
costs more than ordinary RAM -- memman.com charges
$238 for a gigabyte of DDR compared to $100 for
standard PC133 memory -- but prices are falling as
Athlon gains wider acceptance.
Misgivings about compatibility with applications built
for Intel processors are unfounded. The Athlon MP
mimics Intel CPUs perfectly, even emulating Intel's
digital media acceleration technology. Intel will
probably maintain its lead in clock speed. Despite
this, AMD wins many speed contests (including two of
our BAPCo tests) due to its innovative design. All
three of these dual-processor platforms would be good
investments, but the price/performance crown belongs
to AMD.
Tom Yager is the technical director of InfoWorld's Test
Center. E-mail him at tom_yager@infoworld.com.
To join, or start, a discussion on this or any IT-related
topic, please visit our InfoWorld forums at
forums.infoworld.com. Here you can interact and
exchange ideas with InfoWorld staff and other readers. |
