rain of a 32-bit Windows NT workstation rivals that of RISC-based systems. Intel now has a solid hand in the NT game.
Although Windows 95 supports 32-bit applications and data paths, critical components such as USER and GDI still contain large portions of 16-bit code, thus sabotaging the Pentium Pro's complex superscalar microarchitecture (see the story in this month's News & Views). To take advantage of the Pro's improved performance, you need to run a true 32-bit OS such as NT. If you're sticking with Windows 95, go with a fast Pentium, perhaps the new 166-MHz model.
The Early Pro Players
The
four 150-MHz Pentium Pro systems
we cover in this review come from major vendors: Dell, Digital, Gateway, and Hewlett-Packard. Dell also sent us a preproduction 200-MHz system, as did ALR (see the sidebar
"Pentium Pro Hits 200"
). For comparison, we include test results from the dual 150-MHz Pentium Pro I
ntergraph TDZ-400 we reviewed last month (see
"3-D Without RISC,"
January BYTE).
The Dell Dimension XPS Pro150 and the Gateway 2000 PG6-150 are based on Intel's Aurora PCI motherboard. Like Intergraph, engineering companies Digital and Hewlett-Packard developed their own motherboards, adding workstation-level features such as error-correction code (ECC) system memory and built-in SCSI-2 controllers. Also like the TDZ-400, HP's Vectra XU 6/150 has two 150-MHz Pentium Pros. Digital's Celebris XL 6150 keeps its single Pentium Pro on an upgradeable processor board.
All these machines use Intel's Orion 82450 PCI chip set. The Orion provides both a PCI bridge and a memory controller. Like the Intergraph TDZ-400, the Digital system uses the GX version of this chip set, which supports up to four processors and two PCI bridges. The other systems use the KX version. The GX provides ECC protection for the data bus; the KX version doesn't. With the one- and two-processor systems reviewed here, the
only potential advantage of the GX over the KX is that the GX supports four-way memory interleaving, not just two-way. Neither the Intergraph nor the Digital systems came with enough memory SIMMs to do a four-way interleave. All the reviewed PCs have a two-way interleave.
Decked out for testing with 64 MB of RAM, a large hard drive, a 4-MB graphics card, and a 17-inch monitor, these systems go for between $6500 and $10,000. Much of that price is attributed to the RAM.
In the Lab
We tested low-level 32-bit CPU performance using BYTEmark 1.0. We benchmarked component-level performance, particularly hard drive speed, with NSTL's InterMark NT. With BYTEmark, we found that the 150-MHz Pentium Pro performs, on average, 2.6 times faster than our 90-MHz Pentium baseline system in FPU operations, and 2.1 times faster during integer operations. These results place the Pentium Pro in the same general performance range as RISC-based workstations (see
"Processor C
omparison-BYTEmark Results"
). We found a similar improvement when we ran the 32-bit application tests, somewhere between 2 and 2.5 times faster.
To assess motherboard performance, we tried to keep peripheral subsystems comparable in all the test machines. We chose Matrox's 4-MB MGA Millennium card as the common graphics component because it's widely available and fast. Dell's Pentium Pro systems come with a Number Nine Imagine 128 card, so we tested it both with that card and with a Millennium. Under NT, the Matrox was somewhat faster in most tests. (Dell does not support the Matrox card.) Hard drive performance is a big factor we found impractical to control, although we tested the Gateway with both an EIDE and a SCSI drive. The SCSI drive gave the best overall results, though not with all applications.
To measur
e 32-bit application performance
, Bapco's SYSmark for NT 1.0 test suite served us well (see
"SYSmark NT Results"
). It consists of seve
ral Windows NT-based business applications: Microsoft's Word 6.0, Excel 5.0, and PowerPoint 4.0; Welcom Software Technology's Texim Project 2.0e; and Orcad's MaxEDA 6.0.
Intel provided us with a SYSmark-like test that involves high-end NT technical applications: Adobe Photoshop 3.0.4 for NT; Virtual Reality Laboratory's Vista Pro 3.13, a 3-D landscape-generation program that uses fractals (it's FPU-intensive); Pixar's Typestry 2.0, which creates shaded 3-D images from normal text; and MathSoft's Mathcad Plus 5.0, a technical mathematics program with 2-D and 3-D graphical problem solving. The Photoshop component of the test takes advantage of multiple processors under NT and draws excellent performance from the dual-processor systems in this review (see the
"High-End Technical Applications Index"
results). Likewise, North Coast Software's multithreaded PhotoMorph 2.0 for NT let us measure symmetrical multiprocessing capabilities.
In addition to 32-bit testing under NT 3.51, w
e also tested 16-bit performance under Windows 3.11 using Bapco's SYSmark 95 for Windows, a test made up from Windows 3.x applications. With these 16-bit tests, a 150-MHz Pentium Pro system
is barely faster than
the 90-MHz Dell Dimension XPS P90 we used for comparison purposes (decked out temporarily with 64 MB of RAM and a Matrox graphics card).
Dell Dimension XPS Pro150
Dell's 150-MHz Pentium Pro system comes in the standard, lightweight Dimension case. With Intel's motherboard, the Dimension supports one CPU, located directly below the 200-W power supply and next to an exhaust fan. Intel's PCI motherboard provides the foundation for both the Dell and the Gateway systems, and although it doesn't support two processors, its ZIF socket allows you the possibility of an upgrade. However, neither system has upgradable CPU voltage regulators -- that circuitry is soldered down -- so you wouldn't be able to upgrade to future lower-voltage models of the Pentium Pro.
Though the Dell system uses parity-type SIMMs, it provides ECC capability (correct one bit, detect two) through the Intel PCI chip set. The chip set calculates ECC values and stores them in the parity bits. Eight bits is enough to store ECC with a 64-bit memory bank. (Standard ECC SIMMs do error correction internally, on the SIMM.) Dell also uses 60-nanosecond SIMMs, compared to the slowe0-ns SIMMs used in Gateway's system.
In spite of the faster memory, the Dell comes out slower than the Gateway because the Number Nine card holds it back a little, and the Gateway has a faster hard drive (SCSI). With a Matrox card, the Dell catches up to the Gateway only when the Gateway has an EIDE drive like the Dell.
Gateway 2000 PG6-150
The PG6-150 comes in a rugged full-size tower chassis with lots of room inside for drives. Gateway equipped its PG6-150 system with a fast SCSI disk drive that makes a difference in disk-intensive applications, such as project management and graphics pr
esentation programs, allowing it to compensate for its 70-ns memory. Like the Dell, it has four PCI slots for expansion.
A major drawback to using the PG6-150 as a serious workstation is that it has neither ECC nor parity protection for system memory. We doubt anyone will want to run a critical application on this machine with more than 32 MB of unprotected memory. That may put the PG6-150 into the category of a very hot Windows 95 machine, although new 150- and 166-MHz Pentium systems may provide equal performance for less money, given the old 16-bit code still hanging around in Windows 95.
Digital's Celebris XL 6150
With the ability to hold up to 512 MB of memory, built-in SCSI-2, and six levels of security, Digital's Celebris XL 6150 can well handle server tasks. It's also upgradeable, either by swapping the CPU in its ZIF socket on the processor card (it also has an upgradeable CPU voltage regulator) or by switching the processor card itself for one with two Pentium Pros or
even one carrying a fast Digital Alpha chip.
Intel's PCI 82450GX chip set and eight SIMM banks reside with the CPU on the processor card. The main system board has six more SIMM banks. Like the Dell, the Digital system implements ECC through the Orion chip set. Both EIDE and SCSI-2 are embedded, but networking is not. The Celebris hangs back with the Dell in our performance tests despite a fast SCSI hard drive. The machine's use of 70-ns system memory is part of the problem, but that kind of memory doesn't seem to hold the Gateway PG6-150 back.
HP Vectra XU 6/150
HP's dual Pentium Pro system is the top performer in the 150-MHz class for several reasons. It has a 128-bit-wide memory bus and a very fast SCSI drive with a spin rate of 7200 rpm. It uses dual in-line memory modules (DIMMs) for system memory, which provide a 64-bit data path (compared to 32-bit for the SIMMs used in the other systems). Although Intel's Orion chip set allows a 128-bit memory path using four SIMMs per
bank, it's more practical with DIMMs (two per bank).
As a high-end system, the Vectra XU 6/150 provides ECC memory and built-in SCSI. The SCSI chip supports Ultra SCSI (20 MHz). HP also gives you a Fast Ethernet (100VG/10Base-T) PCI card and integrated Sound Blaster capability. The Vectra, in a mini-tower chassis, is nearly the same size as the Dell. However, the Vectra's power supply is around twice the size of the Dell's, and the unit holds two 150-MHz CPUs.
Because of its reliable design and great performance, we highly recommend HP's Vectra XU 6/150, especially if you have an application that can use two CPUs. If you don't need networking or top performance, Dell's Dimension XPS Pro150 provides a lot of power for its price. It's around $1000 less than the HP for a similar configuration.
WHERE TO FIND
Evolution Dual6
Advanced Logic Research, Inc.
Irvine, CA
(800) 444-4257
(714) 581-6770
fax: (714)
581-9240
http://www.alr.com
Pentium Pro Makes NT Fly
