Lower clock speeds less efficient at load

[Shining Arcanine]

A few years ago, I recall reading an article at either Tech Report or Anandtech that claimed that Intel had investigated what the optimal power management strategy was for a computer processor under load and they found that it was more energy efficient to let the processor run at its maximum clock speed, rather than reducing the clock speed. This was around the time that performance per watt became an issue and sites started having charts showing how much energy systems consumed while doing benchmarks.

I am trying to find the original article that had this information, but I have having trouble finding it. Does anyone know where I can find it?

 

[ShawnD1]

http://www.tomshardware.com/reviews/intel-atom-efficiency,2069-12.html

We also tracked the total power both systems used to complete the SYSmark 2004 SE run measured in watt-hours. This metric gauges system performance per watt hour. Thanks to its faster performance, the Core 2 Duo E7200 system on the Foxconn G31 motherboard required 40 Wh to complete the entire benchmark, while the Atom machine, which is substantially slower, required 46 Wh and a much longer period of time (see diagram on the bottom of this page) to complete the workload. The Core 2 machine may require more power at peak loads, but less power for the specific workload. Expect the result to be more significant in favor of the Core 2 for processor-intensive workloads.