Inside Intel's Itanium

Unless you're willing to sift through technical minutia and swim through murky marketing hype, you could miss the potential benefits of Intel Corp.'s Itanium processor. Intel has projected a lengthy evolutionary time line for Itanium and is dropping hints that systems built on its first 64-bit CPU, the Itanium that's available now, will be niche machines.

Intel's caution is justified; neither the processor nor the platform that supports it is currently tuned for maximum performance. Even so, considering the level of performance the processor will ultimately deliver, Intel can afford to be a little less reserved about Itanium.

The Itanium CPU deserves attention for its innovative design; however, the enterprise server platform that Intel built around Itanium is the real star of this show. We've been testing the platform in the form of a prerelease implementation of Hewlett-Packard Co.'s rx4610 four-processor Itanium server, running the HP-UX and Red Hat Inc.'s Linux operating systems, as well as Microsoft Corp.'s 64-bit preview of Whistler. Based on our experience with HP's rx4610, the first generation of Intel's 64-bit architecture should give low-end and midrange Unix systems from Sun Microsystems Inc. , IBM Corp., and HP a run for their money.

What Itanium systems lack in core performance, they will make up for in value and openness. Itanium systems will allow IT shops to run their pick of commercial or open-source operating systems; expand with affordable, interchangeable, off-the-shelf components and peripherals; and play Itanium OEMs against one another on price and policies. In the long run, the Itanium platform will bring Unix system prices down and make proprietary system vendors more responsive to customers' interoperability demands.

Companies running applications on or developing applications for HP-UX or Linux should begin auditioning Itanium. Midrange Itanium servers, such as HP's quad-CPU rx4610, are worth considering for a wide array of applications. At present, only the HP-UX operating system is polished enough to run on Itanium, although Linux is close behind. Windows shops and those requiring maximum overall performance should wait for the Itanium platform to mature.

Itanium's EPIC story

Itanium's design, the product of a partnership between Intel and HP, centers on a concept called EPIC (explicitly parallel instruction computing). All modern CPUs have some capability of running multiple instructions (low-level commands such as add, multiply, or read from memory) simultaneously. Most CPUs analyze software on the fly, looking for opportunities to process instructions in parallel. EPIC shifts responsibility for this analysis from the CPU hardware to the programming language compiler used to create the application.

The result is a simpler CPU design and more consistent exploitation of the processor's capabilities. Eventually, as compilers get smarter and the Itanium platform evolves, EPIC's true potential will be revealed. But at its present level of implementation EPIC delivers not so much a leap as a step forward in terms of overall performance.

Intel's niche marketing campaign, which targets scientific, digital-media, cryptographic, large-database, and Web-caching uses, came about when the company realized Itanium's strengths: floating-point math and data handling. Floating-point calculations are used in everything from encryption to digital video encoding. Intel claims that the Itanium CPU executes as many as 8 floating-point operations concurrently, compared to two for its 32-bit CPUs. And with four processors running at 733 MHz, that's a lot of floating-point power in one box.

Data handling is a loose term for loading, manipulating, and storing information in memory or on disk. Itanium accelerates data handling by copying data from slow memory to a fast internal cache while the CPU does other things.

No CPU is an island

Of course, before a processor can so much as beep at you, it needs a supporting platform, the circuitry or "chip set," to provide the CPU input and handle its output. For Itanium, Intel created a quad-processor platform that, as exemplified by the HP rx4610, sports enterprise-class reliability and manageability. The Itanium platform specifies an EFI (extended firmware interface) that controls the server's boot configuration. The boot menu that once resided on a fragile hard drive is now located in durable nonvolatile memory.

The EFI has a shell mode that's similar to a DOS command prompt. From the prompt, you can perform basic file-management tasks (including text editing), make configuration changes, or write scripts that execute at boot time. Unlike a PC BIOS, the EFI can access DOS-formatted hard drive partitions, LS-120 SuperDisk disks, and standard CD-ROMs. Direct access to files simplifies management considerably. To kick off the installation of the Red Hat 7.1 beta, for example, we simply used the EFI shell to run the install program on the Red Hat CD.

Itanium will be unfairly held back until IT can begin to think of Intel and Microsoft as separate entities. Among the operating systems available for Itanium, Windows trails the pack. Commercial HP-UX software developers already target Itanium, giving that OS a ready library of applications. Almost everything on Red Hat's three-CD beta distribution worked flawlessly on our rx4610, and we had no trouble compiling two projects from sourceforge.net.

Commercial AIX and Solaris developers will have little difficulty porting software from one 64-bit platform to another. Windows users and developers will have the most work to do: They must supplant all of their 32-bit tools and applications with 64-bit equivalents before Itanium will be any more useful to them than a Pentium 4.

Every computer system must be evaluated in its intended setting, and Itanium servers are no different. Our advice is to test Intel's 64-bit server platform in areas where midrange Unix servers, even those from mainstream vendors Sun, IBM, and HP, would be deployed. If your applications do enough number crunching and data hauling, you may see a performance benefit that tips the value scales in Itanium's favor. If you're currently relying on servers that lack the Itanium platform's build quality and reliability features, you may find Itanium servers among the least expensive systems deserving of the "enterprise" label.