A main point of discussion at last month’s Intel Developer Forum (IDF) in San Francisco was the challenge of increasing server performance while lowering power consumption.
Deva Bodas, principal engineer with Intel’s digital enterprise group, has been saying over several IDFs that there is going to be a problem with the power. “Irrespective of [server] utilization, the power drawn is constant,” said Bodas. “It is nothing new, but what has made this worse is that where customers previously had 10 servers, they now are adding hundreds or thousands of servers.”
He added that while the number of servers has grown tremendously, so has overall demand for energy, which has increased the cost of it for companies. Bodas discussed several techniques for optimizing power and performance of server platforms during a session at IDF. The goals of these techniques, he said, is to get the same performance while using less power.
One way to reduce power, he said, is to go to a halt state when the systems are idle. “It (means) turning off the many engines in the processor and getting a power reduction,” said Bodas.
But if the servers are executing instructions, Bodas said using demand-based switching (DBS) will help reduce power consumption. An ingredient that is part of DBS is ACPI, or Advanced Configuration and Power Interface, which enables operating systems to control the amount of power given to each device attached to a computer. For example, ACPI can turn off peripheral devices when not in use or power up automatically once the keyboard is touched.
Using Intel’s Foxton technology is another method of boosting the performance of a processor and, when combined with DBS to reduce power, will give the processor a higher performance-per-watt rating.
In order to optimize performance, Bodas said one needs to lower the number of instructions and interrupts on the processors as well as equalize the load. The impact of an unbalanced load results in lower performance and higher utilization of power.
While testing these techniques to improve power efficiency, Bodas observed that the component that consumed the most power was the power supply. Finding the right size rails and using a higher efficiency power supply should help reduce power consumption.
Another thing Bodas observed was that temperature also impacted power utilization.
“Even if (the processor is) idle, the temperature goes up and the processor and voltage regulator went from 35 to 65 watts,” Bodas noted.
“We need to pay attention to is how we select components in seeing where the power problem is,” he said. One of the things that developers should focus on is redundancy of components like power supplies, drives and cooling systems.
“Pay attention to customer requirements. Build redundancy only if it is needed.” he said.
Bodas is investigating software that, when the workload is offloaded and balanced, improves performance and reduces power consumption.