In-Depth

IBM Pushes Power as an x86 Alternative

It might sound like a long shot, but a recent price/performance showdown between IBM’s Power system and an x86 server suggests otherwise

• By Stephen Swoyer
• 11/30/2004

Last month, IBM Corp. announced the OpenPower 720, a new eServer platform that combines the performance of its Power5 RISC chips with some of the mainstream features of volume Intel servers from Intel Corp. and Advanced Micro Devices Inc. Designed exclusively to run Linux, Big Blue is pushing the new OpenPower 720 where most other RISC-based systems fear to tread: the cutthroat market for commodity servers.

With a starting price of less than $5,000, the OpenPower 720 is downright cheap—at least compared to other RISC-based systems. It can be populated with four 1.5 GHz or 1.65 GHz Power5 processors, the same chips Big Blue uses in its pSeries Unix servers. But unlike pSeries, OpenPower won’t run AIX. Instead, it’s certified for SuSE Linux Enterprise Server 9 (from Novell Inc.) and Red Hat Enterprise Linux. It’s available in four-way rack or tower configurations and can support up to 64GB of system memory.

IBM has slated OpenPower for a market segment—the SME server space—in which commodity servers from Intel or AMD dominate. In fact, some folks have all but written off RISC—be it UltraSPARC, PA-RISC, MIPS—in this market.

What’s surprising, says Thomas Deane, an analyst with consultancy Illuminata, is that OpenPower 720 actually compares favorably with x86 servers from volume market leaders such as HP on a price/performance basis.

Deane used published results in the SAP Sales and Distribution Standard Application Benchmark to compare the performance of a four-way (1.65 GHz) OpenPower 720 with that of an HP ProLiant DL585 outfitted with four AMD Opteron 2.4 GHz processors.

He chose the SAP benchmark because it’s regularly and successfully used to size systems for real-life business applications. Elsewhere, Deane says he chose the ProLiant DL585 because its performance numbers are representative of most of the four-processor Opteron servers tested.

As an added bonus, pricing for both systems is competitive: the ProLiant DL585 costs $29,160; the OpenPower 720 is $31,412. But pricing alone doesn’t tell the whole story, Deane says, because OpenPower 720 customers get more hardware for their money.

“While the price of the OpenPower 720 is 7.7 percent more than the DL585, the OpenPower 720 had an additional 4 GB of memory and had an additional 79 GB of disk space,” he writes. “So despite being a ‘high volume’ product, the Opteron system is not really a clear price-winner here. It's just that the OpenPower 720 has a little more hardware; this accounts, in part, for the additional cost.”

As far as performance is concerned, the OpenPower system outstripped the HP ProLiant by 12.2 percent. “So pay 8 percent more and get a 12 percent performance increase—not too shabby,” writes Deane. “This works out to the OpenPower 720's having about 4 percent better price/performance [ratio] than the Opteron system—an unexpected win.”

Of course, OpenPower probably isn’t the best fit for everyone. After all, customers can run a variety of different operating environments on the ProLiant DL585; on the OpenPower 720 they can choose between two different flavors of Linux. But that’s not the only drawback, Deane concedes.

“OpenPower systems offer less choice than x86-based systems in another way as well. IBM is the only manufacturer of the OpenPower 720 and the POWER5 processor that it is based on. Generally, a single source for anything is a disadvantage for the customer,” he notes. “On the other hand, it's not like IBM is going to go away anytime soon. Furthermore, AMD is the only manufacturer of Opteron and Intel is the only manufacturer of Xeon/EM64T. Though sold in higher volume than POWER5, they, too, are single-sourced.”