Energy Efficient Data Center source : http://hightech.lbl.gov/presentations/6-23-05_PGE_Workshop.ppt&ei=BVxPVIy_Bse68gWwy4HAAw&usg=AFQjCNGHU_rSwcF4BMo2A6KnFfSZglP2UA&sig2=wZlTGXORD_HOUDJi-a2uAA&bvm=bv.77880786,d.dGc

1. Energy Efficient Data Centers
Update on LBNL data center
energy efficiency projects
June 23, 2005
Bill Tschudi
Lawrence Berkeley National
Laboratory
Wftschudi@lbl.gov

2. LBNL’s energy research
related to data centers
 Energy research roadmap
 Case studies and energy benchmarking
 Best practice identification
 Self benchmarking protocol
 Investigate efficiency of power supplies in IT
equipment
 Investigate efficiency of UPS systems
 Metrics for computing performance vs. energy
 Technology transfer
 Demonstration projects

3. Data center efficiency opportunity
 Many efficiency ideas have been
identified through industry feedback
 Case studies are helping to identify
best practices

4. Data center efficiency resources
 ASHRAE “Thermal Guidelines for Data Processing
Environments”
 ASHRAE “Power Trends and Cooling Applications”
 In preparation: ASHRAE “Design Considerations for
Data Center and Communications Equipment Centers”
which includes a chapter on energy efficiency

5. Case studies/benchmarks
 California
• Storage device and router
Mfgs.
• Banks
• Web hosting facilities
• Internet service provider
• State tax center
• Federal facilities
 New York
• Recovery center (hosting)
• Financial institution

6. IT equipment load intensities
Data collected in 1999 through 2003 showed
that electrical power intensity for IT equipment
alone was on the order of 25 Watts/sf.
Current data suggests that load intensities are
rising through compaction and/or due to rising
equipment power consumption.

7. 2003 IT equipment loads
from LBNL case studies
Computer Load Density
70
60
50
40
30
20
10
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Facility
W/sq.ft.
Average 27 +/-
(W/sf of electrically active floor space using Uptime definition)

8. 2003 projections if fully loaded
Current and Projected Load Intensity
100
80
60
40
20
0
Projected
Average 44
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Facility
W/sq. ft.
Current Computer Load Projected Computer Load
(W/sf of electrically active floor space using Uptime definition)

9. Distribution of computer load intensities
reported to Uptime Institute
1.00
0.80
0.60
0.40
0.20
0.00
Source: Uptime Institute, 2002.
0 20 40 60 80 100
Computer room UPS power (Watts/square foot)
Fraction of total floor area in sample
1999
2000
2001
Number of
facilities Total floor area
Computer room
power density
Million square feet W/square foot
1999 35 1.55 22.9
2000 38 1.72 22.4
2001 48 1.86 25.3

10. 2005 IT equipment benchmarks
IT equipment load
100
90
80
70
60
50
40
30
20
10
0
1 2 3 4 5 6 7
Data center identifier
Watts/sf
LBNL NERSC
supercomputer
Average 52
w/sf

11. Electrical power conversion
is a big opportunity
Every conversion of AC voltage, AC to DC, DC to AC,
or DC voltage conversion results in loss of electrical
power and corresponding heat that must be removed
from the data center. Minimizing this conversion loss
has a magnifying effect that allows all facility systems to
use less energy and consequently the infrastructure
systems can be downsized.
Saving say 10% on the conversion loss could result in
20% or more saving for the facility.

12. How many times do data centers convert
In Out
Inverter
Bypass
Battery/Charger
Rectifier
Internal Drive
External Drive
I/O
Memory Controller
m Processor
SDRAM
Graphics Controller
5V
12V
3.3V
12V 1.5/2.5
AC/DC DC/DC
DC/DC
AC/DC Multi output PS
V
1.1V-
1.85V
12V
3.3V
3.3V
Voltage Regulator Modules
PWM/PFC
Switcher
Unregulated DC
To Multi Output
Regulated DC
Voltages
AC and DC?
AC voltage conversions

13. Measured UPS efficiency

14. Measured UPS losses

15. Measured UPS losses

16. 131
Electricity use in a server
32 32
72
41
86
27 32
140
120
100
80
60
40
20
0
AC DC
Losses
DC/DC
Losses
Fans
Drives
PCI Cards
Processors
Memory
Chipset
Based on a typical dual processor 450W 2U Server;
Approximately 160W out of 450W (35%) are losses in the
power conversion process (Source: Brian Griffith: INTEL)

17. Power supply opportunity
2380
85
170
1190
4335 340
HVAC Chilled Water
Standby Generator
Lighting and Plug
Loads
UPS Losses
Computing Load
HVAC Fan Load
Efficiency
of Power
Conversion
Process
IT Load
(kW)
UPS
Losses
(kW)
Total
Savings
(kW)
65% 4335 340 0
70% 4025 316 334
75% 3757 295 623
80% 3522 276 877
85% 3315 260 1100
90% 3131 246 1299
Based on one case study approximately 4335 KW of a total of 8500 kW was IT
load. Assuming a 65% existing baseline efficiency, the savings opportunity using
90% efficient conversion process is approximately 1300kW not including any
savings from HVAC

18. Power supply efficiency recommendations
The Server Systems Infrastructure group (SSI)
publishes recommended minimum efficiencies
for server power supplies. The LBNL project
team is working with this group to see what can
be done to raise the bar.

19. Power supply efficiency today
68
Full Load
Efficiency >
68%
Redundant System of Power Supplies for Servers

20. Measured power supply efficiency

21. Energy efficiency opportunity
Specifiers of UPS’s or IT equipment can have a huge
impact on energy use by requiring higher efficiencies.
Testing data shows that higher efficiencies can be
obtained – you have to ask for it. Facility and IT
professionals by working together can optimize overall
power conversions. Additional costs (if any) for more
efficient conversions will have a very short payback or
may be entirely justified by reductions in infrastructure.

22. HVAC (as a % of total load)
60%
50%
40%
30%
20%
10%
0%
1 2 3 4 5 6 7 8 9 10 11 12
Data Center Identifier
% of total load
Effectiveness of HVAC systems

23. Index of performance
The Uptime Institute proposed a metric to
evaluate the total efficiency of infrastructure
systems:
Index of performance = building systems KW ¸
UPS output
(i.e. ratio of building systems to IT equipment
load)

24. Look at the end-use
Data Center A Data Center B
Computer
Loads
38%
UPS Losses
6%
Lighting
2%
HVAC
54%
Total Power = 580
kW
UPS Losses
13%
HVAC - Air
Movement
9%
Computer
Loads
63%
HVAC -
Chilled Water
Plant
14%
Lighting
1%
Total Power = 1700 kW

25. LBNL high-tech buildings website:
http://hightech.lbl.gov