The Making of Energy Efficient Datacenters

The Crooked E: The Unshredded Truth About Enron is a wonderful movie to watch. It is based on the book, The anatomy of greed, written by a former employee of Enron, Brian Cruver. One interesting thing that comes on our minds is the size of all power companies. They are all huge. We all depend on power for just about everything and yet very rarely do we think about conserving energy. A typical PC for example takes about 135 watts of power. A data center with about a 1000 servers should typically take about 135 x 1000 Watts or 135 Kilowatts and that would just power the computers. This does not include the air-conditioning and lighting. According to to a research paper sponsored by The California Energy Commission in a datacenter about 50% of the total energy consumed is by the servers and about 35% is the air conditioners.
Here are some interesting research done in this field -
Feeling the heat- An interesting paper by Liebert describing the challengeof effectively managing the heat dissipation in datacenters. Heat-Density Trends in Data Processing, Computer Systems, and TelecommunicationsEquipment- This white paper provides valuablecurrent data and best available insights regarding historical andprojected trends in power consumption and the resulting heatdissipation in computer and data processing systems (servers andworkstations), storage systems, and central office-typetelecommunications equipment.
This problem can be solved by making better energy efficient airconditioners and by making more energyefficient computers. Many companies have taken a lot of interestin subject. However, nothing substantial has been done primarilybecause of the market requirements. The end users still want to hosttheir sites on the fastest processors which drives the market with thelatest processors. Going at this rate we would reach a time soon whenthe energy required would be much higher than the energy available inthe market.

Intel, AMD, Transmeta and Via have all released processors whichconsume very low power. A typical Pentium or AMD processor consumesabout 25 Watts of power, whereas these low powered processors take onlyabout 5 watts of power i.e. about 5 low powered processors wouldconsume as much power as a single main stream processor of today. Theselow powered processors are also generally fan less processors whichmeans lower noise levels too. Intel has the centrino which has a lowerpower consumption than the regular pentiums. Intel also has the armprocessors but those are RISC. Our prime focus would be AMD, Transmetaand Via. They all have some very promising products.

One thing to be noted is that most of these low powered processors workonly at about 1.2GHz or lower. So they won't be as fast the pentium4s.Which means one would have to host lesser sites per server. A goodrecommendation would be upto a maximum of 600 sites on aregular pentium 4 server. A low powered processor should comfortablytake about 200 sites. One advantage of these low powered processors isthat they have a very small form factor too. This means that one canhave more such servers in the same space that is typically allocated toa high powered servers. All datacenters use a profitability matrixbased on the following rule: Performance/PerWatt/Per Cubic Foot. This is one place where the low poweredprocessors really score high.


AMD Geode? NX Processor familycomprises of the AMD Geode? NX 1250@6W processor, the AMD Geode?NX 1500@6W processor and the AMD Geode? NX 1750@14W processor. Thefirst two in these consume only 6Watts of power and run without acooling fan. According to AMD they provide the highest x86 performancefor fan less operations. They are based on the mobile AMD AthloNPRocessor technology.

Transmeta was one of the first companies to develop low powered processors.For a long time Transmeta was known as the company where theMicrosoft co founder Paul Allen had interests in and the placewhere Linus Trovalds, the father Linux, worked. Both of them are nolonger part of the organization. Today they are known for the twoprocessor families they have - The transmeta crusoe andthe transmetaefficeon

Transmeta Crusoe?-processors range from 500Mhz to 1.2 Ghz. According to Transmeta,Crusoe is a unique combinationof software and hardware. It's this radical design that gives Crusoe itsimportant advan