Andrew Kutz

Thesis ◦ The energy efficiency of today’s information technology (IT) infrastructure is not doubling every two years along with performance, leading to very high performing, very inefficient data centers. The inefficiencies in energy consumption must be mitigated so that efficiency will catch up with performance. 2

Agenda ◦ Power in the data center today ◦ Areas for improvement ◦ Recommendations 3

Agenda ◦ Power in the data center today  Data center power distribution  Data center power consumption  The result ◦ Areas for improvement ◦ Recommendations 4

Data center power distribution 5 HVAC Room, misc.Power distribution unitsRacksCompute Servers CPU Storage UPS Storage devices Power StationBackup Generator(s) PSU

Data center power consumption ◦ The breakdown leaves room for plenty of areas of improvement. 6 IT equipment Server components 40 % 60% 35% 30% 20% 15%20%15% IT equipment Power delivery Cooling equipment Compute servers Storage servers Comm. & misc. CPUs CPU VR loss Memory HDDs and misc. PSU loss Data center Source: Dell, APC, SUN

The result 7 75x 16x Source: Christian Belady

Agenda ◦ Power in the data center today ◦ Areas for improvement  Processors  Power supplies  Power delivery  Cooling ◦ Recommendations 8

Processors – Last gen processors were power hungry beasts! ◦ A first-generation AMD Opteron (856) at 3.0GHz used 92.6W ◦ According to AMD, processors can use between % of rated power when in an idle state. ◦ That means the same processor was consuming W of energy when doing nothing. 9

Processors – Multi-core CPUs ◦ Multiple cores on a single chip and processor development helps to reduce energy consumption  An Intel Xeon 3.80 GHz used110W  An Intel Xeon E GHz Quad-Core uses 80W.  2.45 times the processing power at.72 times the energy consumption! 10

Processors – Power stepping CPUs ◦ CPUs can step down into reduced performance modes by adjusting frequency and voltage in synchronization with load. 11 Source: AMD

Power supplies – Today’s problems … ◦ The typical efficiency of today’s power supply is anywhere between 75-80%. ◦ % efficiency means 100kW is being radiated into heat that cooling systems must remove. ◦ 100kW equals 341,400 BTU. ◦ At 0.10 USD/ kWh it costs 52, USDover a 4 year life cycle to remove the extra heat. 12

Power supplies – Are tomorrow’s opportunities ◦ Power supplies being developed with digital feedback control can maintain 90-95% efficiency over a wide range. ◦ % efficiency means only 20kW, or 68,280 BTU, is radiated as heat. ◦ At 0.10 USD / kWh it costs 14, USD over a four year life cycle to remove the extra heat. ◦ Increasing PSU efficiency by 20% reduces wasted cooling costs by four fifths. 13

Power delivery – Uninterruptible Power Supplies (UPS) ◦ UPS devices are long-term investments. However, it may be time to upgrade. ◦ May lose.59% efficiency for every year a UPS device is in service. That is a potential improvement of 10.03% for upgrading a UPS from Source: Eaton Power

Cooling – Inefficiencies ◦ General cooling is a guaranteed way to generate hot spots, resulting in wasted energy. ◦ Over-cooling – Cooling systems are often designed to run at maximum capacity at all times, resulting in wasted energy. 15

Cooling – Improving Efficiency ◦ Targeted cooling and right-sizing  The closer the cooling is to the source of the heat, the better.  While it is tempting to buy big, only so much cooling is needed. Any more than is needed is wasted energy.  Take off the sweaters! ◦ Remove the …  The heat – the biggest barrier to cooling is heat!  The gaps – seal cable cut-outs and install blanking panels. ◦ Investigate liquid cooling  Or how I learned to stop worrying and learned to love the H2O.  APC, IBM, Liebert are offering liquid cooled rack solutions. 16

Direct Current (DC) Power Delivery ◦ Pros  Delivering DC power directly may offer greater energy efficiency by reducing the number of distinct AC  DC inductors.  One side effect would be reducing the amount of cooling required per server since excess heat in the AC  DC conversion is localized to fewer areas. ◦ Cons  Only one major vendor (Rackable Systems) currently offers full DC support in its x86 server product line. This could lead to vendor lock-in.  Although used for years by the TelCo industry, the number of engineers experienced in DC power vs. AC power is small. 17

Cooling – Improving efficiency (continued) ◦ Variable Frequency Drives (VFDs)  A subset of adjustable speed drives (ASDs).  Adjusts speed by altering the frequency and voltage output.  Cooling equipment with VFDs can dynamically adjust the speed of the fan based on different input factors such as static pressure using a pitot tube and manometer.  Reducing the output voltage when extra cooling is not need leads to less energy consumption. 18

Agenda ◦ Power in the data center today ◦ Areas for improvement ◦ Recommendations  Technical  Business  Community 19

Technical ◦ Remember, CPUs represent almost 10% of a data center’s power consumption. ◦ Rethink power and cooling designs and systems. ◦ Explore consolidation efforts:  Compute  Virtualization  Blades  Storage  Shared storage – SANs, Filers  Storage designs – massive array of idle disks (MAID), data deduplication 20

Technical ◦ Delivering DC power directly to the servers sounds like a good idea, but it should be classified under “wait and see.” 21

Business ◦ Make the power and cooling issue a bold line item on the CxO’s budget. ◦ Consider creative options:  Rent roof space to local utilities companies for solar panels and buy back cheap energy.  Move the data center to a colder climate. ◦ Pressure vendors to think green. Purchasing power is the greatest bargaining tool that customers have. ◦ Every percent counts. A 400kW data 0.10 USD / kW = 245, USD / year. 1% will result in an annual savings of 3,504 USD. 15% = 36, USD. 30% = 73, USD. 22

Community ◦ Join organizations, such as the green grid, that are dedicated to helping to build an energy efficient data center. ◦ Pay attention to existing and emerging standards like Green Grid’s Power Usage Effectiveness (PUE) when buying new equipment to ensure energy efficiency. ◦ The Energy Star is expanding to cover servers. ◦ Encourage vendors who are already thinking green to keep it up: Fujitsu-Siemens, NEC, IBM, HP, Dell, and Sun to name a few. 23

◦ The opportunity to increase efficiency will probably not disappear while electricity prices are not prohibitively expensive and compute power is cheap. ◦ The government and industry initiatives are developing and will continue to fine tune energy efficiency related standards. Efficiency used to be Power Out / Power In. It will be transformed to Productivity Out / Power In. ◦ To have the most effect, attack the largest culprit first – processors. CPUs account for almost 10% of a data center’s energy consumption. Save the power leader, save the world! 24

◦ AMD – PC_WP.pdf PC_WP.pdf ◦ APC – 6CN8PK_R0_EN.pdf 6CN8PK_R0_EN.pdf ◦ Christian Belady – cooling.com/articles/2007/feb/a3/ cooling.com/articles/2007/feb/a3/ ◦ Dell – s1q CoverStory.pdf s1q CoverStory.pdf ◦ Intel – 25