Author's note: I can't provide this article exactly as it appeared in BYTE magazine, as the second-billing cover story in the May 1998 issue because BYTE's publisher, McGraw-Hill had sold the magazine to CMP Publications, publisher of Windows magazine. Miller-Freeman has since bought CMP. I grabbed it from DTK's web site with the company's gracious permission. The electronic version never contained my "Tech Focus" sidebar about shrinking chip dimensions or my sidebar about how identical machines had different performance yields (some had disabled L2 cache ECC to shave nanoseconds). Also missing is a two-page spread of comparative characteristics of 19 systems from 18 vendors.
-Dan Tanner (June 6, 1999)

BYTE Magazine - May 1998 / BYTE Hardware Lab Report / 333-MHz Pentium IIs: Slow-Bus Swan Song


333-MHz Pentium IIs: Slow-Bus Swan Song


May 1998 / BYTE Hardware Lab Report / 333-MHz Pentium IIs: Slow-Bus Swan Song

Fast CPUs wring the ultimate in performance out of slow-bus NT systems.

Dan Tanner

Deschutes is Intel's code name for the fast new Pentium II chips built using the 0.25-micron CMOS process. Ironically, these recently introduced 333-MHz processors are also the fastest Intel CPUs currently running on the soon-to-be-updated 66-MHz system bus motherboards. That makes these machines somewhat akin to dinosaurs, albeit extremely fast dinosaurs.

BYTE Lab evaluated 19 333-MHz Deschutes systems running NT 4.0 Workstation. All use the 66-MHz bus and 440LX chip set on the motherboard. As the difference in clock speed predicts, they're about 11 percent faster than their 300-MHz cousins. Increasingly, it's slow components and the 66-MHz system bus, not the processor, that stifles PC performance.

Fortunately, 66-MHz motherboards are about to become a thing of the past, at least for high-end PCs. Deschutes PCs built around 100-MHz motherboards, clocked from 350 to 450 MHz, should make their debut about the time you read this.

Several manufacturers opted to wait out this 333-MHz round-up, choosing to submit PCs with 100-MHz motherboards and faster processors. They arrived too late for a comprehensive report (look for one in the June BYTE). The 100-MHz system bus is definitely a technology for future expansion. Our preliminary tests using the new bus and today's components show performance gains of 2 to 9 percent over similar 66-MHz systems. We predict you'll need faster memory and applications that use newer technologies, such as Accelerated Graphics Port (AGP), to realize major speed gains.

AMD and VIA are already building chip sets to support systems with 100-MHz motherboards; expect to see Deschutes competitors from AMD and Cyrix supporting this interface later this year.

Where Deschutes Fits

This first Deschutes chip, and those shipping in the next few months, will still fit the same proprietary Intel Slot 1 motherboard interface as today's Pentium II. Later on, Deschutes-series PIIs will likely migrate to the newer Slot 2 connector.

Like the Klamath series, Deschutes CPUs now come packaged in a single-edge contact (SEC) cartridge. Within the SEC, the processor core and industry-standard burst static RAM (BSRAM) Level 2 (L2) cache are enclosed in plastic and metal and are surface-mounted.

Later Deschutes-series PIIs, with full-speed backside buses, will require Intel to replace commodity BSRAMs with custom static RAMs (CSRAMs). BSRAMs require one clock cycle to read and another to rewrite data, so their top speed is half that of the CPU. The CSRAMs are limited-quantity proprietary Intel parts that can run at a full 450 MHz (i.e., with their 64-bit interface, at 3.6 GBps).

Deschutes and Klamath have the same P6 microarchitecture, including support for MMX, 32 KB of Level 1 (L1) cache, and (for the first Deschutes chip) a 66-MHz frontside bus. Both include an external 512-KB BSRAM L2 cache contained in the SEC cartridge. Both support Intel's 440FX/440LX chip sets and others from third parties. The current CPU interface and chip sets, however, limit them to a two-way multiprocessing implementation. Error-correction code (ECC) is available on the L2 cache of the Deschutes.

Pentium II's pipelined system bus allows multiple simultaneous transactions. Like the Pentium Pro, the PII speeds up performance at a given clock speed by using dynamic execution, Intel's term for branch prediction. The processor predicts which way branch instructions will fork (with a claimed 90 percent accuracy) and speculatively executes some instructions along the predicted path, rearranging them to take maximum advantage of the chip's resources.

Market Splash

Deschutes may have a bigger impact on the processor market than on overall system performance. Intel released the 333-MHz version at $721, $200 below the usual price for its top-line PC processor, and only two months later dropped that price almost 20 percent, to $583. As might be expected, the prices of previous-generation Pentium IIs tumbled.

Intel also cut prices on Pentiums for mobile computers from 15 to 51 percent, although desktop Pentium Pro prices remain unchanged.

The second half of 1998 will see a new Deschutes series, this time with 256 KB of on-die L2 cache.

Best Overall

The DTK APRI-76M/P333 has no elaborate, expensive engineering features. Using a basic motherboard, standard options and memory, with an acceptable 17-inch monitor, the DTK has managed to keep a low price. At the same time, it scored top marks for performance.

Controls are conveniently located, with a primary power switch on the back panel to shut off the juice to the power supply as well as the more conventional power-on button in front. Inside, there's easy access and plenty of room for an extra CD-ROM, tape, or Zip drive. Besides the expected mouse, keyboard, USB, serial, and parallel ports, the back panel also holds connectors for the AGP video adapter, external SCSI, 10/100 Ethernet, and an x256K modem. The inside of this machine is simple and straightforward, offering easy access for repairs or upgrades.

Kingdom's Pinnacle 333 Power system came in second in our Best Overall scorings, largely due to an excellent technology implementation. Like the third-place Xi machine, this PC can support up to 1 GB of RAM on the motherboard.

Don't overlook NEC's nifty PowerMate Professional 9000 and SAG's fast STF3300. Priced at less than $3200, both offer technology options you'd expect to see in higher-priced machines. They have a second processor slot for an additional CPU, for example, and free up an extra slot by integrating SCSI on the motherboard. The NEC's 64-bit PCI slot offers an upgrade path for the future, and its NEC 32X CD-ROM drive is one of the best on the market.

Best Value

The $2799 DTK system, with the third lowest price of all systems tested but lowest price of our top seven performers, also won honors as Best Value. It offers 10/100 Ethernet as standard equipment, a Toshiba 32X CD-ROM drive, a good-quality ELSA Gloria Synergy video card with 8 MB of SGRAM on-board instead of the more usual 4 MB, and a large 300W (its maximum output) power supply at a very reasonable price.

The $2599 Micron ClientPro 766Xi was fourth in Best Value. Its performance kept it out of the running for Best Overall system, but the machine managed to incorporate a good feature set -- 4.5-GB Ultra Wide SCSI hard drive and 8-MB Number Nine video card -- and still come in as the lowest-priced machine.

While the $3724 SysTech and $3750 Compaq PCs were among the more expensive machines tested, their combinations of great features and high usability made them our second and third choices, respectively, for Best Value.

The Bottom Line

With the 66-MHz system bus on the way out, at least for high-end PC workstations, does buying one of these machines make sense? If you're in the market for high-performance bargains, our response is an unqualified "You bet."

Prices for these 333-MHz units are, in many cases, less than half the price of the 300-MHz systems we reviewed in our January issue (see the Hardware Lab Report "Eight Heavy-Hitting NT Workstations").

We expect that prices of Pentium PCs will continue to fall, possibly precipitously, as the 100-MHz system bus makes its debut and new sub-$1000 PCs utilizing Intel's Celeron and other low-cost chips become popular.

If performance and upgradability are your chief concerns, however, you may want to wait out this round for even faster machines emerging in the next couple of months. Next-generation 350- and 400-MHz machines, supported by the faster system bus and faster components, likely will add to the overall cost of the PC, but the improvements in speed and compatibility with future upgrade paths might be worth the extra cost.


Test Methodology

Question: When is 333/90 greater than 3.7?

Answer: When you're comparing Pentium II performance to original Pentium performance, back in the days when 90 MHz reigned supreme.

BYTEmark evaluates processor and memory performance. We base our results on an index system, in this case a Dell 90-MHz Pentium PC. If the clock speed of the processor under test is 333 MHz, one might expect performance scores of 3.7.

The enhanced architectures of new Pentium systems can achieve much higher scores. Our top-rated DTK machine scored an integer index over 4.75; floating-point was nearly 5.33.

Changes in Pentium II architecture can take the credit for this feat; many PII instructions are simply more efficient. Integer Multiply (IMUL), for example, has been trimmed from 10 clock cycles on a Pentium to three cycles on a PII (see "Which Compiler Is Fastest?," January BYTE). In addition, the Pentium II employs such speed-up methods as dynamic execution.

BAPCo SYSmark Results

BAPCo SYSmark tests exercise real-world applications running native-mode code under Windows NT 4.0. BAPCo chose Microsoft Excel and Word for typical office operations, Texim for project management jobs, and Layout Plus for CAD work.

BAPCo's test applications provide intense system exercise, including file I/O that works a hard drive heavily. The spreadsheet and word processing applications are integer-intensive; BAPCo's CAD application generally emphasizes floating-point operations.

Our Photoshop Test

The BYTE/Van Horn Photoshop benchmark is an integer-intensive test using the functions that graphic artists with Adobe Photoshop 4.0 would employ. The file used for the test is large, over 8 MB, to ensure that memory calls go far beyond the range of the processor's cache.

Photoshop interpolation was set to Bicubic. We eliminated video-card performance differences from these scores. The following tests were performed:

Methodology

Every configuration we examined met the following specifications:

Processor: Intel Pentium II/333-MHz (Deschutes)

Chip set: Intel 440LX

Operating system: Microsoft Windows NT 4.0 Workstation, with a separate installation of Service Pack 3

Memory: 64 MB

Hard drive: Minimum 4-GB SCSI, controller on motherboard or PCI card

File structure: NTFS

Graphics adapter: AGP adapter, minimum of 4 MB of video memory

Monitor: 17-inch color, 1024x768 resolution, true color (24-bit), 75-Hz refresh rate

No other applications, including virus shields, TSRs, or applets, were running during the tests. Nonessential start-up applications or placeholders that could be using memory were removed before testing.


Evaluations in this report represent the judgement of BYTE editors based on tests conducted in BYTE's laboratory. For full documentation of the benchmarks, visit the BYTE Web site at http://www.byte.com; see http://www.byte.com for the BYTEmark, http://www.bapco.com for BAPCo data, and for the Van Horn Photoshop tests, see "MMX: Better in Fits and Starts," February BYTE (magazine or CD-ROM), or visit the BYTE Web site.


Best Overall: DTK APRI-76M/P333

The DTK APRI-76M/P333 not only won Best Overall honors, it placed first in our price/value rankings (see below). Last September, the company's entry also garnered the Best Overall award in our testing of 17 233- and 266-MHz Pentium II systems.
ProductPricePerformanceTechnologyImplementationBest Overall
BB=DTK APRI-76M/P333$2799*******************
Kingdom Pinnacle 333 Power$2997*****************
Xi 666 Tower DP$3199******************
NEC PowerMate Professional 9000$3199******************
SAG STF 3300$2945******************
SysTech Sys Performance Pro 333LS$3724****************
Compaq Deskpro 6000 6333X/4300/CDS$3750 ****************
Key: BB = BYTE Best. ***** Outstanding **** Very Good *** Good ** Fair * Poor. Weightings: Best Overall: Performance 70%, Implementation 15%, Technology 15%.


Best Value/Low-Cost: DTK APRI-76M/P333

DTK Computer's APRI-76M/P333, selling for $2799 in the configuration we tested, was one of the lowest-priced systems submitted to us for review. And although other systems were faster in individual tests, it came in as the top overall performer, easily making it our choice for Best Value.
ProductPricePerformancePrice RatingFeaturesUsabilityBest Value
BB=DTK APRI-76M/P333$2799************************
SysTech Sys Performance Pro 333LS$3724********************
Compaq Deskpro 6000 6333X/4300/CDS$3750*******************
Micron Electronics ClientPro 766Xi$2599********************
Everex StepStation 2$2730*********************
Kingdom Pinnacle 333 Power$2997*********************
Xi 666 Tower DP$3199*********************
Key: BB = BYTE Best. ***** Outstanding **** Very Good *** Good ** Fair * Poor. Weightings: Best Value: Performance 50%, Price 30%, Usability 10%, Features 10%.