The 64-bit question

When Intel Corp. introduced the Pentium III Xeon processor'the first of its 32-bit CPU lines designed specifically for enterprise computing'it opened the door for manufacturers of Intel servers to compete with RISC system manufacturers such as Compaq Computer Corp., Hewlett-Packard Co., IBM Corp. and Sun Microsystems Inc.Four-way and eight-way Pentium III Xeon servers have been ideal for most midrange and back-end server systems, and in some cases have edged out RISC systems as the preferred platforms for mission-critical enterprise applications.Pentium III Xeon CPUs operate at speeds between 700 MHz and 900 MHz, and come with 1M or 2M of Layer 2 cache and up to 32G of synchronous dynamic RAM. They are based on Intel's Profusion chip set and feature three 100-MHz buses'two processor buses and one I/O bus.Xeon systems also feature four PCI bridges supporting 10 64-bit PCI slots, four of which are either 66-MHz PCI slots or 100-MHz PCI-X slots, and six others which are 33-MHz PCI slots. They include error-correcting code (ECC) to increase data integrity and reliability, System Management Bus for providing platform-level management features such as processor information and thermal sensing, and Extended Server Memory Architecture to support up to 64G of memory.As good as Xeon systems are, they don't quite scale the heights of high-end computing. Intel has taken a step, albeit a tentative one, toward the next level with Itanium, the first of its 64-bit processors.Itanium, delayed several times during its development and released commercially last spring, is based on Intel's new Explicitly Parallel Instruction Computing (EPIC) technology and, like the Xeon, was designed to provide high availability, scalability and performance for high-end enterprise and technical computing. Systems have been slow to catch on; sales were modest through the end of last year.But Intel intends to make its 64-bit chips standard in future systems and is developing the next generation of Itanium, currently code-named McKinley.Itanium processors are designed for applications requiring large database computations, online transaction processing, secure business intelligence and high-performance technical computing. They come in 733-MHz or 800-MHz versions and three levels of cache: 2M or 4M of Level 3 cache, 96K of Level 2 cache and 32K of Level 1 cache. Their 266-MHz data buses can handle plenty of transactions with up to 2.1G of bandwidth.The EPIC architecture delivers increased parallelism, huge register sets, high floating-point performance as well as large memory addresses.Itanium processors use 256 64-bit rotating registers. These act like an assembly line by applying the same operations to a stream of data, and the technology is of particular benefit when large database sort routines and technical floating-point calculations are required, according to Intel.The company also claims that Itanium processors can achieve up to 12 times the performance levels of proprietary RISC systems'a feature that is especially useful for enhanced e-commerce transactions.The EPIC architecture's ability to rapidly execute encryption and authentication processes could make Itanium servers ideal for protected e-business environments. A four-way Itanium system can handle more than 1,350 secure transactions per second.The chip's Machine Check Architecture enables the system processor, firmware and operating system to work together to contain and fix processing errors. And its ECC memory detects and corrects data errors in both Layer 2 and Layer 3 cache, and offers Layer 1 parity checking. Other reliability features such as hot-pluggable PCI components, redundant fans and power supplies come standard or can be added by system vendors.Intel contends that 64-way and larger systems will become more readily available as market demand for them expands. Future Itanium servers will provide up to 256G or more of main memory, and clusters of Itanium servers will also allow data centers to 'scale out' by adding more systems as demand increases.Meanwhile, current Itanium servers support 32-bit applications, meaning users can protect their investments in existing 32-bit systems. As for third-party support, Intel said that vendors have already committed to developing more than 400 server and workstation applications for Itanium platforms. Operating systems under development include Hewlett-Packard's HP/UX 11i v1.5, Microsoft Corp.'s 64-bit Windows Advanced Server Limited Edition 2002 and various flavors of Linux.Though its journey to mainstream computing was fraught with delays and bugs, the future of 64-bit processing seems assured. The Aberdeen Group, a high-tech marketing and research company in Boston, has predicted that Itanium servers will account for 42 percent of worldwide server revenue by 2005. Compaq has announced that Itanium processors will power all its servers by 2004. Dell, Hewlett-Packard and NEC Computers Inc. have voiced similar support.Will Intel eventually scrap its Pentium III Xeons and other 32-bit processor lines in favor of the Itanium? The official company line is that it won't. But, of course, that's likely to change if 64-bit computing catches on.For the present, you won't have to make difficult and costly decisions about the phase-out of 32-bit Intel server architectures in favor of new, more powerful 64-bit ones. Intel's strategy is that there's room for both. For the next few years at least, this will be true.