Data Center Power Consumption: What Effect Does Memory Have?

Data Centers now account for 3% of the worldwide power consumption, up from an estimated 1.5% just a few years ago. Data centers have been getting more efficient, but the efficiency has been hidden by the large growth in the number of data centers.

The question that was recently posed to me: What effect does memory have on data center power consumption?

I’ll cut straight to the chase. The memory in the data center, including overhead, accounts for about 20% of the total data center power consumption. While not the biggest power hog, memory offers an opportunity to improve overall efficiencies.

Like most questions that get asked of me, I started doing some research to try to ascertain the relevant data. Without doing my own teardown analysis of both the data center itself, as well as a teardown of a typical server that might be found in the data center, I was able to find some interesting data.

First, let’s start with the data center itself. A common metric for data center efficiency is the PUE – the power usage effectiveness, or the ratio of total data center power to the power used for the equipment (e.g. servers). A PUE of 1.0 would represent perfection – all power coming into the data center is used directly by the IT equipment, and therefore no extra power was being used for things like electrical conversion losses or cooling. Recent, self-reported survey data from the Uptime Institute indicates that the PUE of a typical data center today is 1.65. In other words, for every 100 watts required by a server, 65 additional watts are needed to provide for electrical losses and cooling.

It stands to reason that if we can lower the server’s power consumption, we also can lower the amount of data center overhead.

Next, we need to better understand the insides of the server, and how much of an individual server’s power consumption come from memory. Similar to the overall data center, a server also has power inefficiencies due to cooling and electrical losses. Depending on the memory configuration chosen, memory accounts for 20% of the power used by the server’s components. Eliminating a portion of the memory’s power consumption leads to reduction of the server power overhead, as well.

As new memory technologies get introduced, the memory industry has placed a strong focus on reducing power consumption, while simultaneously providing more bandwidth and storage capacity. Recently introduced DDR4 memory will soon supplant the DDR3 memory currently in vogue in the data center, reducing DRAM power consumption by more than 35%, leading to an overall data center power consumption reduction of almost 8%.

I have confidence that even looking beyond DDR4, the memory industry will continue to innovate, further shrinking the power consumption in the data center. The best is yet to come!