News

Intel Releases Next-Generation Xeon MP

• By Scott Bekker
• 03/12/2002

The Intel Xeon MP comes in speeds of 1.4 GHz, 1.5 GHz and 1.6 GHz, although the primary performance gains come from a 4X improvement in front-side bus speed, a new L3 cache and the Hyper-Threading capability that allows one physical processor to function with the speed of two logical processors in certain situations.

The processor replaces the three-year-old Pentium III Xeon processor line that powered four-processor and greater Intel architecture servers since 1999. The Pentium III Xeon line for multiprocessing topped out at 900 MHz.

Intel Xeon MP is based on the NetBurst microarchitecture of the Pentium 4. Intel expects the architecture to last long enough to support processor frequencies around 10 GHz.

"We see [the Intel Xeon] lasting for the foreseeable future in terms of IA-32 -- out past the '05 timeframe," says John Cartasegna, product marketing manager for Intel's IA-32 processor line. "You'll see a coexistence between Itanium processors and IA-32 processors for the foreseeable future."

Four-processor servers represent by far the biggest sales volume target for the chip. But it is also the processor that will power the eight-way servers from a number of vendors, along with the 16-processor servers on IBM Corp.'s roadmap and the 32-processor servers Unisys Corp. delivers. Two-processor servers use the Intel Xeon DP processor Intel launched in late February.

At this point, Intel is relying on OEMs and third parties to deliver chipsets for the Intel Xeon MP, which supports DDR 200 memory. The processors use a 400-MHz front-side bus and support up to 32 GB of main memory in a four-processor system. Few Pentium III Xeon systems with four processors shipped with -- or needed -- more than 8 GB of RAM.

The amount of memory provided in the new L3 cache is less than the old L2 cache of the Pentium III Xeons, but Cartasegna points out that the new architecture makes the comparison meaningless.

"It increases the throughput to the processor core itself. The architecture of the cache allows for higher bandwidth through the cache than the previous architectures of the cache that we had," Cartasegna says.

The new L3 cache comes in 512 KB or 1 MB versions, with 256 KB of L2 cache. Intel is not yet discussing its roadmap for increasing those amounts.

Hyper-Threading is a completely new technology in the Intel Xeons. It is also present in the Intel Xeon DP. Hyper-Threading allows the processor to simultaneously handle threads produced by applications, making it theoretically possible for each processor to behave as two processors.

Jay Bretzmann, director of xSeries server marketing at IBM, says the technology has potential to greatly increase scalability of systems, but both ISVs and customers have to change the way they use the systems to reap the benefits.

"Customers need to understand that they need to load up on these processors more than they did with Pentium IIIs. There aren't a lot of applications that throw off more than 2-3 threads," Bretzmann says.

For now, Intel claims scalability benefits of 20 percent to 36 percent on enterprise applications and online transaction processing (OLTP) database workloads based on the processor alone.

The company provided its own test runs of four-processor systems running Windows 2000 Advanced Server on the mySAP Supply Chain Management application. Intel says it got a 36 percent improvement using the 1.6-GHz Intel Xeon compared with the 900-MHz Pentium III Xeon. Comparing the same sets of processors, Intel got a 20 percent improvement on an unspecified OLTP database workload.

Mark Feverston, vice president of Unisys Server Programs, says his company's projections for customers who drop the new Xeons into their big Unisys systems are about the same.

"We predict that this particular new processor from Intel will provide about 20 percent performance improvement to most commercial application customers," Feverston says.

Despite the new processor features, Intel will not seek a premium over what it previously charged for its top-of-the-line multiprocessing chip, the 900-MHz Pentium III Xeon with 2 MB of L2 cache. Like the 900-MHz PIII Xeon, the 1.6-GHz Intel Xeon MP with 1 MB of L3 cache will cost $3,692 each in 1,000-unit quantities.

The 1.5-GHz model with 512 KB of L3 cache will cost $1,980, the amount Intel previously charged for the 700-MHz PIII Xeon with 2 MB of L2 cache. The 1.4-GHz Xeon MP with 512 KB of L3 cache will cost $1,177, the previous cost of the PIII Xeon at 700 MHz with 1 MB of L2 cache.

Intel did not immediately provide the new pricing for the Pentium III Xeons, but the company does plan to continue to offer them in the near term.