Server benchmarking lone wolf bites Intel again

Neal Nelson, an independent engineer who conducts server benchmarking tests, is claiming that Advanced Micro Devices' Opteron processors are generally more energy efficient than Intel's Xeon processors.

According to Nelson, if your data center has a lot of AMD-based servers, your power consumption and costs may be lower than they are at facilities that are weighted toward Xeon-based systems.

There has been no independent review of Nelson's claims thus far, and he said that in many respects, he is out there by himself in doing independent benchmarking of the energy efficiency of servers. Intel, for one, is almost dismissive of his findings.

But Nelson's data may get an outside review by year's end. That's when Standard Performance Evaluation (SPEC), a non-profit company that develops computing benchmarks, is expected to publish a new test suite for comparing server efficiency.

Nelson said he thinks the two benchmarks will be similar. Like his test suite, the one being developed by SPEC is designed to measure server power usage directly from the wall plug.

Chip vendors typically measure the energy efficiency of their processors, not servers as a whole. Meanwhile, server vendors may provide power usage information with their products, but there currently is no standardized benchmark for comparing the energy efficiency claims of different vendors.

Nelson compared the power consumption of the Xeon 5160 and Opteron 2222 chips on a pair of servers, using the Apache Web server, MySQL database and memory capacities ranging from 2GB to 8GB. He said that the Opteron-based systems did better in 36 of the 57 tests he ran.

The difference was most stark when the servers were at idle, Nelson said. In those cases, his tests showed that the Opteron-based server was anywhere from 30 percent to 53 percent more efficient than its Xeon-based counterpart. He said that for operators of large data centers, where servers can sit idle for long periods of time, the higher efficiency could add up to big power savings.

The energy efficiency benchmarks follow an earlier round of performance tests that Nelson conducted on the two server processors. He released the results of the earlier tests last January, saying that a single-core, 2.4-GHZ Opteron delivered more than twice the peak performance as a similar Xeon device did.

Intel, though, claims that it has the most energy efficient chips on the market. In a short statement, the company said that Nelson's latest benchmark "ignores performance, in that you'd use less Intel servers to get the same job done, meaning less electricity is needed."

Nelson called Intel's contention incorrect and said that he compared throughput as well as efficiency. Intel also faulted his tests for not measuring its new quad-core Xeons, but Nelson said he would have wanted to compare those devices with similar processors from AMD that have yet to be released.