Both Advanced Micro Devices and Intel Corp. are working hard these days to create low-power high-performance microprocessors for servers as power consumption and heat dissipation are becoming major problems of modern datacenters. According to Neal Nelson, an independent computer performance consultant, AMD’s Opteron HE “Shanghai” platforms are more efficient compared to low-power Intel Xeon 45nm platforms.

“The AMD-based server beat the Intel based server in our tests. We processed millions of transactions against a real database and we measured the total throughput and the total power used by the servers,” said Neal Nelson, president of the consulting firm.

The servers were tested with three different transaction workloads: a calculation intensive workload, a disk I/O intensive workload and the "idle" state when the server was powered up and waiting for transactions to arrive. The entire test suite was run twice, first with 4GB and then with 16GB of main memory.

The servers used in this test had virtually identical configurations. The only notable differences were that the Intel server had an 8% faster clock frequency with 2.5GHz versus 2.31GHz and the Intel server used fully buffered memory modules (FB-DIMMs). It should be noted that Intel is about to roll-out Xeon processors based on the Nehalem micro-architecture with integrated memory controller. Therefore, the results will be mostly outdated in several months time.

For the calculation intensive workload the Opteron reported 1% to 6.3% higher throughput.

The disk intensive throughput tests ranged from 1.1% favoring the Xeon to 5.0% favoring the Opteron.

The power consumption, however, favored the Opteron in every test with a range of 13.1% to 20.8%.

When the power readings were normalized by throughput the Opteron advantage ranged from 21.8 to 26.8%.

The net effect of architectural differences between AMD Opteron and Intel Xeon platforms (the main difference is integrated memory controller in AMD chip and external memory controller that supports only FB-DIMM in case of Intel Xeon) is that an currently available Intel-based server can draw more power at the platform-level when compared to an AMD based server that delivers comparable throughput. A server's total throughput and total power consumption are much more important than whether some individual computer chip consumes more or less power.

The Nelson test results should not be confused with power usage test results from the Standard Performance Evaluation Corporation (SPEC).  The SPECPower test was created by a committee of engineers from computer manufacturers (including Intel).  SPEC ssues a disclaimer which specifically states that the test results may not predict real world experiences, according to the consulting firm.

Tags: AMD, Intel, Xeon, Opteron, Shanghai, 45nm