Xeon, the Pentium II processor that Intel Corp. designed specifically for workstations
and multiprocessor servers, arrived at the GCN Lab hot off the production line in a Dell
Computer Corp. Precision 610 Workstation.
Intel does not compare the 400-MHz Xeon against its own processor family. Instead, its
Web site at http://www.intel.com/businesscomputing/wrkstn/techfocus/benchmarks.htm
holds up the Xeons performance to that of chips in Unix workstations from Sun
Microsystems Inc., Silicon Graphics Inc. and other workstation makers.
In the labs tests, the 400-MHz Xeon with 512K of error-correcting-code Level 2
cache edged an average 400-MHz Pentium II with 512K of synchronous dynamic RAM by about
31/2 percent in math benchmarks. In heavy-cache areas such as video rendering, the Xeon
screamed past the Pentium II.
Intel sells Xeons with up to 1M of ECC L2 cache and plans to offer 2M.
How cache works is a little complex, but think of it as an amusement park where lots of
people are wandering around. The people represent the processes the computer performs.
Every amusement park has a featured ride, usually the roller coaster. Xeon represents
this speed demon. L2 cache is the long line in which visitors stand, like processes
waiting to get into the Xeon.
Level 1 cache, which is far smaller than L2, amounts to 32K in a Pentium II. Its
analogous to the front of the queue, where the visitorsor processesseparate to
be seated on the roller coaster. At each tick of the clock, the processes hop on board to
take their ride through the processor.
L2 cache used to operate at the same speed as the motherboard. For example, in a
standard Pentium II with the 100-MHz BX chip, the L2 cache ran at 100 MHz. But the
processor was whisking processes from the L1 cache at 400 MHz, while the L2 cache line was
advancing at only one-quarter of that speed. A slight bottleneck developed.
The Xeons L2 cache on the GX chip operates at 400 MHz, the same speed as the
processor and L1 cache. So all the processes are in lockstep, and the line for the roller
coaster moves four times as fast.
The Xeons performance gains look minimal on a basic office benchmark such as the
GCN Labs GCNdex32TM suite. The test processes are nowhere near as challenging as a
full rendering of a 3-D computer-aided design drawing.
A better gauge is OpenGL 3-D rendering. A standard 400-MHz Pentium II at XGA resolution
with true-color depth renders up to 30 frames per second. Some graphics accelerator cards
might cause it to render more slowly, but generally a top-of-the-line system does 30
frames per second.
On the Xeon, the lab recorded 40 frames per second, the fastest speed ever achieved by
a desktop computer in lab tests. And on the 2-D GCNdex video tests, the workstation
recorded another high score of 28.14.
Some of this tremendous performance came courtesy of the Accelerated Graphics Port X2
Multimedia Permedia 2 video card from Diamond Multimedia Systems Inc.
Dell also sent another AGP X2 card, the Intense 3D Pro 3410 from Intergraph Corp. It
added about $1,000 to the cost, but the Intergraph card produced even higher 2-D scores of
32.06 and rendered more than 70 frames per second in 3-D.
I almost wanted to slow down the Precision to get a better look during the renderings.
The hard-drive scores might appear to be a little slow compared with standard Pentium
IIs. But most systems running Microsoft Windows NT do have slower hard-drive
benchmarks because the operating system shuttles disk reads through the processor, unlike
Windows 9x, which leaves the processor out of the disk access.
Nevertheless, the Precisions Ultra SCSI hard drive tore along, although the
10,000-revolution-per-minute disk whined noisily. A Precision WorkStation can accommodate
two processors and up to four drives.
Dell continues to refine its OptiPlex desktop design, maintaining one-button access to
the interior. Expandability is excellent; two exterior and three interior bays are
Expect to pay about $4,500 for a Precision 610 with Diamond Permedia 2 graphics
Other options quickly raise the price to more than $8,000.