Xeon Speeds by Eight-way Pentium Pro

Now that the bugs are worked out of Intel Corp.’s first installment of the Pentium II Xeon processor, and servers are shipping with it, the first credible benchmark results are showing just how fast systems based on Intel’s latest processor can be.

Now that the bugs are worked out of Intel Corp.’s first installment of the Pentium II Xeon processor, and servers are shipping with it, the first credible benchmark results are showing just how fast systems based on Intel’s latest processor can be.

In one of the key metrics, Transaction Processing Performance Council (TPC, San Jose, Calif., www.tpc.org) benchmark results of the TPC-C test suite are setting new standards for Wintel systems.

In fact, Compaq Computer Corp., NEC Corp. (Melville, N.Y., www.nec.com) and Unisys Corp. (Blue Bell, Pa., www.unisys.com) are duking it out over who has the fastest four-way Xeon server. The actual leader isn’t as important as the fact that four-way Xeon machines have been benchmarked at more than 18,000 transactions per minute, which represents a 40 percent -- and in some cases as much as a 60 percent -- performance increase over four-way systems built on Pentium Pro chips. The transaction per minute cost (tpmC) results published by TPC for Compaq and Unisys Xeon systems translate into a price/performance ratio of approximately $25 per tpmC, the most advantageous ratio for Wintel customers to date.

On top of outperforming four-way Pentium Pro-based systems, four-way Xeon-based servers are also speeding by eight-way Pentium Pro test results. Hewlett-Packard Co.’s eight-way NetServer LXr Pro8, one of the fastest eight-way Pentium Pro servers measured under TPC guidelines, produced 16,257 tpmC at $34 per tpmC. That performance number is less than what new four-way Xeon systems are routinely achieving.

Comparisons between Xeon systems and Pentium Pro machines are inevitable because, despite being the successor to the Pentium Pro, the Pentium II processor was not widely used as a server engine in multiprocessor machines. "It isn’t exactly fair to compare Xeons with Pentium IIs because there really are no true four-way or eight-way Pentium II servers, since that chip doesn’t scale beyond two-way processing," says Pat Buddenbaum, product marketing manager for Pentium Xeon, Intel enterprise server group.

Analysts expect the Xeon to find a home as a server engine, in part because of the internal construction of the chip. "The Xeon systems are built on a different architecture, and Intel made major improvements over the PII," says Rob Enderle, senior analyst, Giga Information Group (Santa Clara, Calif.), a market analysis firm.

Those improvements include enhancements to the system bus, PCI bus and cache, all of which are instrumental in boosting processor performance. "Historically, we said, ‘To judge the performance of a system, look at the clock speed,’ but that’s no longer true," says Tim Golden, director, enterprise server product marketing, Compaq. "Now there are a lot of factors tied to the processor that contribute significantly to system performance."

The most significant enhancement -- yet to be publicly demonstrated -- to the Xeon chip is the ability to scale to eight-way processing. When that happens, vendors promise that performance will nearly double. "We expect to see in the vicinity of 30,000 tpmC," says Intel’s Buddenbaum.

"After four-ways, historically, the performance jump hasn’t been that great, because both NT and the hardware top off at four processors," says Giga’s Enderle. "The belief here is that Intel has improved the underlying chipset enough to allow for scaling to eight-way processing."

Enderle reserves judgment on eight-way Xeon systems, and is waiting to see if performance actually meets the numbers Intel expects to see. But even if it Xeon doesn’t scale as well as Intel claims, vendors are expected to rally around eight-way Xeon systems. "Few vendors were willing to build eight-way PII systems," says Buddenbaum. "But we’ll see most major vendors introduce eight-way Xeon systems at the beginning of next year."

The across-the-board boost in performance is leading to a renewal of NT systems vendors’ interest in the server market traditionally held by Unix machines. "Xeon has opened up a lot of people’s eyes to say that the Intel Architecture is closer to being capable of handling the needs of Unix users," says Don Johnson, vice president and general manager, NT server business, Unisys.

The Xeon processor, which has already demonstrated better performance in server systems than machines built on Pentium Pro, is expected to become the standard for eight-way systems.