Utility Computing
                 • Long been a vision
                 • Grid computing failed to 
                  really catch on
                 • Technology advances as 
                  well as a viable business 
                  model have helped Cloud 
                  Computing catch on
                 • Cloud Computing allows 
                  for fuller utilization of 
                  hardware
                 • Energy consumption is 
                  turning into a major issue
  Is the Cloud Green?
   • 2005 -                           • More recent articles 
      o 0.5% of total world             conflicting
        energy usage and 1.2%            o Some suggest growth is 
        of U.S. energy usage               slowing/has been 
        come from data centers             slower (Reuters, 
      o World usage expected               Koomey)
        to quadruple by 2020,            o Some suggest it is still 
        U.S. usage doubling                increasing 
        every 5 years                      (Networkworld)
 Green Computing
  • In the past 15-20 years of 
   supercomputers
    o performance has 
     doubled > 3000 times
    o performance per watt 
     has doubled 300 times
    o performance per square 
     foot has doubled 65 
     times
 Scaling
 • Dynamic Voltage and Frequency Scaling (DVFS)
   o Intel SpeedStep
   o AMD PowerNow!
 • Started in laptops and mobile devices
 • Now used in servers
 Green Cloud Framework