Itanium Still the 64-Bit Jewel In Intel's Crown

It didn't turn out that way.

However, Itanium 2, which is the second generation of Intel's Explicitly Parallel Instruction Computing (EPIC) architecture, has re-emerged as a healthy competitor in the high-end server and mainframe-replacement markets.

"We sold over 100,000 processors last year," says Mike Graf, Intel's product line manager for Itanium.

Intel achieved that by beating back competition from systems built using high-end RISC architectures, such as IBM's Power, HP's PA-RISC and Sun Microsystems' UltraSparc. Boxes based on the latest speed grades of those chips are being rushed to market. Earlier this year, Sun debuted Sun Fire servers built around its UltraSparc IV. Last month, IBM introduced a line of eServers equipped with its hot new Power 5. And HP's 9000 line showcases its high-performance PA-8800 processor.

According to Graf, the crowded high-end market totals around $25 billion annually for systems hardware alone. "Itanium has a unique set of performance, reliability and scalability features that make it a great competitor for the Power and Sun architectures. It is ultimately our premium product line," he says.

Along with HP and IBM, Itanium-based systems are sold by Bull, Dell, Fujitsu Siemens, NEC, Rackable Systems, Samsung and SGI, among many others.

While X86 processors continue to dominate in low and midrange servers, the needs of the ultra high-end stand apart. "The addition of extended memory technology to Xeon is not a replacement for Itanium," Graf explains.

That's why the Itanium architecture takes a different approach, based on parallelism. It's equipped with numerous execution units and instruction-issuing ports. It also applies software techniques called predication and speculation to extract parallelism from applications and speed up chip throughput.

Itanium 2 is a fully 64-bit processor that runs 64-bit applications compiled for EPIC. It also can run 32-bit code. Unlike hybrid 32/64-bit processors, however, which run existing x86 software natively, Itanium 2 runs 32-bit software via an emulation mode.

The next iteration of the Itanium architecture will be a dual core part. "That will be done next year with a device we're calling Montecito," Graf says. "Montecito will have two logical cores on a single die, 24 MB of on-die cache, over 1 billion transistors, and will also support multithreading technology," he says.

Montecito is expected to deliver a performance increase of one-and-a-half to two times over the existing Itanium 2.