Computer performance consulting firm Neal Nelson & Associates claims (http://www.worlds-fastest.com/wfz991.html) that AMD-based servers have beaten Intel in 36 of the 57 power efficiency tests it has conducted. The tests put an AMD Opteron-based server up against an Intel Xeon-based server.

The firm asserts the report was not funded or sponsored by any outside company or group. Tests were performed on servers configured with 2GB, 4GB, 6GB and 8GB of memory using various transaction processing load levels.

The results show that under certain configurations and load levels, the Intel server was 2.4 to 11.7 per cent more power efficient. But in a majority of cases, the AMD server was 9.2 to 23.1 per cent more efficient.

Perhaps more significantly, when the systems were idle and waiting for transactions to process, the AMD server was 30.4 to 53.1 more power efficient. If accurate, it's a noteworthy figure, considering many servers spend the most of their time waiting for work.

On the whole, NN&A's tests showed that Intel's power efficiency decreases as memory size increases. Conversely, AMD's power efficiency increases as the memory is upped.

The firm uses a home-cooked benchmark — where web transactions are processed against a server configured with Novell's SuSE Linux Enterprise Server, the Apache2 web server software, and the MySQL relational database.

The firm said they conducted the test in response to a statement made by Intel CEO Paul Otellini in July, where he claimed Intel was the leader in power efficiency.

"It appears Mr. Otellini's statement is inconsistent with the test results," said Nelson.

Intel, of course, disputes the results.

"The report doesn't measure our latest Xeons, or quad cores," said Intel rep Nick Knupffer in an email. We have 2 GHz quad cores in the market at 50 watts, 12.5 per core!"

"The report ignores performance, in that you'd use less Intel servers to get the same job done, meaning less electricity is needed."

"We stand behind all our energy efficient claims, period. For those IT managers who don't do their own in-house testing, we recommend that each look at the 100s of independently verified benchmarks and reviews that exist for the most credible assessment."

NN&A's white paper with the meat of their benchmark tests can be found here (http://www.worlds-fastest.com/d.pdf/wfw991.pdf) (PDF) or here (http://www.worlds-fastest.com/d.doc/wfw991.doc) (Word format). ®

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