DDR, Pentium 4: Performance power play

When Intel first announced its support of DDR (Double Data Rate) SDRAM for desktop PCs, it signaled the beginning of the end for the company’s often tumultuous marriage to Rambus. After nearly three years spent singing the praises of the unpopular and costly RDRAM architecture, the industry’s leading chip-maker finally caved in to customer pressure by adding DDR to the official Intel platform road map.

However, the path to memory independence was longer and much rockier than many had expected. Although Intel was aggressively pursuing DDR for its low- to midrange desktop platforms, it was having a much tougher time letting go at the higher end of the computing spectrum. Cycle for cycle, the combination of a Pentium 4 CPU and RDRAM still delivered the best overall performance for mainstream computing tasks. Factor in the 2001-2002 market and mind-share gains claimed by archrival AMD, and it becomes easy see why Intel decision makers were loath to make any change that might jeopardize their already-tenuous speed advantage.

Enter the 875P chip set. With an 800MHz FSB (Front Side Bus) and support for dual-channel DDR-400 memory, the 875P was born to perform. It handily trounces Intel’s previous standard bearer, the RDRAM-based 850E platform, across a range of benchmarks (see “Stacking Up Desktops,” below). This is true despite a CPU clock frequency disadvantage of 66MHz (both the 875P and its midrange sibling, the 865, run the fastest Pentium 4 CPU at 3.0GHz vs. 3.06GHz for the 850E).

Add to this a high-performance, gigabit-scalable networking link — Intel’s CSA (Communications Streaming Architecture) — and support for SATA (Serial ATA) disk drives, including RAID 0 striping, and you have the formula for a lasting performance relationship.

Our three roundup participants, MPC, Hewlett-Packard, and Gateway Computers, are eagerly rushing 865- and 875-based products to market to capitalize on what can best be described as the ultimate rebound scenario for Intel. With performance nearly 20 percent faster than its previous incarnation, the venerable Pentium 4 PC never looked this good.

MPC ClientPro 545: All Muscle, No Fluff

A personal ad for the MPC ClientPro 545 might read: “Hunky, SGM (single, gray-metallic male) with well-tuned hardware seeks demanding workloads for high-bandwidth relationship.” With DDR-400 SDRAM memory, Nvidia Quadro FX2000 workstation-class video, and SATA RAID support, the ClientPro is all business.

I used my Benchmark Studio load-simulation and performance-testing platform — including the Winstone-like OfficeBench linear test script — to run all of these systems through their paces, constructing a complex, multitasking scenario involving database, workflow, multimedia, and office productivity tasks with the concurrent workload simulation features.

This baby was bred for performance and it showed: The ClientPro 545 delivered the best overall times across my demanding multiprocess business computing workloads. When the chips were down and the process load dialed to the max, the ClientPro pulled away from the pack, posting an impressive 18.5 percent performance advantage versus our scoring baseline, the previous generation’s 850E-based Dell Dimension.

Of course, the ClientPro 545 also has a sensitive side, manifested in the various convenience-oriented features: tools-free case design; dual-display capability; and copious front panel connectors (two USB ports of eight total, plus audio). Rounding out the amenities is a 750MB Zip drive, which complements the ubiquitous 3.5-inch floppy disk drive and 48X/24X/48X CD-RW drive with optional DVD.

The ClientPro really shines when it comes to value. At $3,553 as tested, it’s less expensive than the HP Workstation xw4100 but delivers better performance thanks to its SATA RAID 0 support and full implementation of Intel’s CSA. Overall, it’s a great solution for performance-oriented knowledge workers and entry-level workstation applications.

HP Workstation xw4100: Conservative Overtones

If the MPC ClientPro 545 is the buff, gym-going type, the HP xw4100’s personal ad reads more like the mature professional: “Looking for stability via traditional, long-term collaboration with growth potential.”

But don’t let the xw4100’s mild manners fool you. Underneath that stolid exterior hides a true performer that, despite a lack of SATA RAID support, still delivers more punch than its 850E-based forebears. As with the MPC and Gateway systems, the performance advantage is most visible during heavy multitasking of concurrent workloads, where the HP delivers a 7 percent boost versus the 850E baseline.

Still, this only hints at the gains that could have been had with a true SATA RAID implementation. During a combination linear- and parallel-tasking test session, the best that the HP box could muster was 5 percent improvement over our 850E baseline, compared to the RAID-enabled MPC system’s astounding 18.5 percent for the same OfficeBench scenario.

Otherwise, the xw4100 matches the MPC system speed for feed, with identical audio and video components, and a similarly convenient tools-free case design with two front-side USB connectors and one audio. The only real variation and potential cause for concern was its use of a Broadcom GbE (Gigabit Ethernet) transceiver in place of Intel’s chip-set-level solution, which effectively nullifies the advantages gained with the 875P chip set’s CSA support.

Unfortunately, the one area where the HP box really stumbles is in the value equation. For $3,592, you get a 1GB box running at 3.0GHz with a single 160GB disk, plus the vaunted Quadro FX2000 card. It’s a bargain by workstation standards but a bit pricey when you consider that MPC offers more performance for less money.

Gateway 700XL: Radical Results, Consumer Focus

Normally, I wouldn’t feature a system such as the Gateway 700XL in this type of review. The box’s enthusiast and/or gamer focus (its personal ad might best read: “sk8er boi” — enough said) makes this system more suitable for the family room than the datacenter. However, Gateway’s decision to be one of the first to market with an 875P system, coupled with a paucity of enterprise desktop solutions at press time, led me to make an exception.

And frankly, I’m glad I did. Though the 700XL ships with a decidedly game-centric ATI Radeon 9800 Pro video card, the system’s overall performance was on par with the brawny MPC ClientPro 545. In fact, the Gateway kept pace with the MPC under all but the most demanding workloads, outrunning the 850E reference system by a solid 10 percent. Were it not for the lesser video, this may have well been the better performing system.

The SATA solution is identical to the MPC box, as is the integrated GbE with CSA support. The only variation: A Creative Labs Sound Blaster Audigy card replaces the normal motherboard audio — again, gamers rule.

Other notable features include a convenient, tools-free case; front-panel USB and FireWire ports (but no audio connectors); and both DVD-R/RW and CD-RW combo drives. Then, of course, there’s the price: $2,959 with 1GB DDR-400 SDRAM, clearly the most bang for buck of any of the systems tested here.

The Bar Gets Raised

Rambus may not be dead to Intel, but the divorce papers have clearly been filed. As these systems show, Intel now can raise the desktop performance bar using popular — and generally less expensive — DDR SDRAM components.

What they also show is that the nature of PC performance is changing. Whereas you could once focus mostly on CPU frequency when evaluating new PC platforms, you now must consider the larger performance picture: Chip set, memory subsystem architecture, disk and network I/O, and so on.

Today’s systems deliver better performance by incorporating more efficient chip-set technologies — namely, the 800MHz FSB, SATA RAID, and CSA. By improving the supporting cast, the 875P allows vendors to wring additional performance from what is otherwise an unchanged 3GHz Pentium 4 CPU. And it’s why savvy IT shops must now adjust their performance purchase targets upward to reflect the transition from RDRAM to DDR SDRAM. The overall message: Look beyond megahertz and gigahertz when sizing PC platforms.