In-Depth

IBM's New xSeries System Improves Performance, Validates Chipset Choice

IBM’s flagship xSeries server demonstrates how far Intel servers still have to go to reach feature and function parity

• By Stephen Swoyer
• 06/07/2005

Whatever else you can say about it, the new xSeries x460 system IBM Corp. announced last week is a testament to Big Blue’s non-conformist streak.

Taking its place at the top of the xSeries line, the 32-way x460 is also testament to the continuing evolution of Big Blue’s Enterprise-X chipset architecture, which is based in part on seminal ideas and methods IBM first developed for its mainframe, AS/400, and RISC/Unix systems.

In large part because of Enterprise-X, version 3—or X3, for short—IBM officials were unusually ebullient about the new x460, calling it—with little, if any, equivocation—the most powerful x86 server available today.

“As we transition from the second to third generation [of Enterprise-X], we’ve taken a maniacal focus on increasing performance in the subsystem,” says Don Bullock, worldwide product manager for all of IBM’s X3-based servers. In X2, Bullock explains, Big Blue used separate memory and processor controllers; in X3, both are integrated on the same piece of silicon. “We’ve reduced latency by an enormous amount, and X3 offers the best performance of any chipset, including [chipsets developed and manufactured by] Intel.”

That may well be the case, but the x460 also demonstrates how far Intel servers still have to go if they’re to reach feature and function parity with the rest of Big Blue’s eServer line—especially its zSeries mainframes.

IBM the Iconoclast

Big Blue has long bucked conventional wisdom in the commodity server market. Its decision in the late 1990’s to develop Summit, the precursor to Enterprise-X, was conceived as proprietary memory controller and I/O chipset logic for its (soon to be rechristened) xSeries servers. IBM pursued its Summit strategy in spite of the fact that most of its competitors opted to use Intel Corp.’s own SMP chipset CMOS, or—alternately—chipset logic from ServerWorks, now a division of Broadcom Corp.

Or consider IBM’s token show of support for Intel’s IA-64 processor family. Although it did deliver an early Itanium 1 test server, IBM seemed to vacillate when it came to Itanium 2, delivering two system configurations in total. More recently, IBM officials have downplayed the company’s interest in Itanium altogether, emphasizing that x86 is where the market is.

Last week, IBM’s Bullock confirmed that doesn’t plan to release an Itanium-based X3 system—nor any other Itanium 2 systems for that matter. “We will continue to offer the [xSeries] 455 [IBM’s flagship Itanium server system] as long as customers continue to purchase it, and we’ve actually had several profitable quarters with the 455, but we’re not planning on an Itanium version [of X3],” he confirms.

In both cases, IBM bucked an industry consensus, and in both cases IBM’s non-conformist tendencies were prescient. Big Blue’s x86 server market share, for example, has grown by leaps and bounds over the last 24 months, thanks in no small part to the performance and scalability of its Enterprise-X chipset logic. Similarly, Intel’s once-inevitable Itanium has slowly been recast as a niche player, such that x86 servers—and, particularly, x86 systems with 64-bit extensions—really are where the market is.

IBM’s strategy has earned accolades from analysts. Take long-time industry watcher Nathan Brookwood, a principal with microprocessor consultancy Insight64. Sure, Brookwood says, HP and Dell are the volume and revenue leaders, respectively, in the x86 server space, but IBM has come on strong, thanks to Enterprise-X, BladeCenter, and aggressive pricing.

“If you look at the [market share] numbers, IBM is doing really well, gaining [share] at their [Dell’s and HP’s] expense,” says Brookwood. “They went with their own chipset instead of using the Intel twin chipset, and it’s really started to pay dividends for them.”

Charles King, a principal with consultancy Pund-IT Research, agrees. “For IBM, the x460 reflects both the company’s need to differentiate its solutions in the muscular x86 server market and its aim to do so by means of an architecture that differs significantly from competitors’ offerings,” he writes. “During the past two years, as server vendors such as HP and Sun floundered, IBM managed to enhance its x86 profile.”

The 411 on the New x460

The new x460, which Bullock says should be generally available by June 17th, will initially debut in configurations of four or eight processors; Big Blue plans to support configurations of up to 32 processors by July. It’s powered by the latest Xeon MP chips, which run at 3.33 GHz and feature Intel’s EMT64 64-bit extensions. As a result, it can address up to 512 GB of system memory.

Like IBM’s other Enterprise-X offerings, the x460 is also a modular system, which means customers can buy in at a small form-factor—say, a single four-way, 5.25” high rack—and add additional 5.25” high rack units as needed. The x460 will also be compatible with the dual-core Xeon chips Intel is expected to ship next year, at which time customers will be able to run as many as eight processor cores in a single 5.25” high rack.

Mainframe Technology Trickle-Down

IBM’s Bullock says the x460 owes much to IBM’s mainframe, midrange, and RISC-Unix systems, citing chipset-level support for virtualization and memory protection. “We do things inside the X3 chipset that enable better virtualization. IBM is one of the pioneers of the idea of partitioning, where you take a larger configuration and subdivide it, and it’s not just in terms of virtualization, but also in terms of hardware partitioning,” he explains, citing the modular construction of the x460, its 32-way predecessor (the x445) and other xSeries systems.

“It’s capable of being an eight chassis, 32-way processor configuration that can be subdivided into eight four-ways, four eight-ways, two sixteen-ways, and so on. That is an idea that has been employed on mainframes for years.”

Ditto for memory protection, says Bullock. “There are things we do inside of the chipset to improve the reliability, increasing the reliability of the memory subsystem, so we have four levels of memory protection that we’ve introduced into the X3 design to help these systems achieve the highest availability.”

At the same time, says Gordon Haff, a senior analyst with consultancy Illuminata, the kind of virtualization IBM delivers in its Enterprise-X-enabled xSeries systems is a far cry from its own zSeries mainframes, which support the micro-partitioning of individual processors. Recently, IBM introduced support for micro-partitioning on its midrange (iSeries) and RISC-Unix (pSeries) servers as well. Third-party virtualization technologies, such as EMC Corp.’s VMWare, are popular for use on Intel-based systems, and—to a large extent, Haff points out—enable a single processor or group of processors to be effectively micro-partitioned. It’s unfair, Haff suggests, to compare these capabilities with features IBM, HP, Sun Microsystems Inc. and others offer in their high-end hardware lines.

All that being said, analysts believe that IBM’s new x460 is a standard bearer in at least one respect—it’s the most scalable and sophisticated Intel server on the market. In fact, says Pund-IT’s King, the x460 is a pivotal product introduction for Intel, too. “The x460 will likely help bolster Intel’s hopes and efforts, demonstrating levels of performance that deem the 64-bit Xeon well-matched for stringent enterprise and HPC tasks."