The Problem of Power Consumption in Servers L

The Problem of Power Consumption in Servers L. Minas and B. Ellison Intel-Lab In Dr. Dobb’s Journal, May 2009 Prepared and presented by Yan Cai Fall 2009 Green Computing 1

Motivation • Server energy consumption has increased from 50 w to 250 w since 2000 • Energy cost will exceed the server cost if this trend does not change Source: IDC, Scaramella 2006 2

Outline • • • Motivation Where heat comes from How cooling is achieved How power is consumed Conclusions 3

Where heat comes from • Server form factor Pedestal servers 2 U rack servers Pedestal 2 U 1 U rack servers Blade servers 1 U Blade • Server power consumption is affected by server form factor, including § § the individual configuration, the heat and thermal environment the workload being processed … 4

Where heat comes from • The amount of heat, (Q), generated by an integrated circuit is a function of § The efficiency of the components' design (e) § The technology used in its manufacturing process (t) § The frequency and voltage at which it operates (f, v) • Over-clocking also generates a great amount of heat 5

Outline • • • Motivation Where heat comes from How cooling is achieved How power is consumed Conclusions 6

How cooling is achieved • Two common methods § Heat sinks § Fans Natural convection heat sink (Source: Wikipedia, 2008) 7

Outline • • • Motivation Where heat comes from How cooling is achieved How power is consumed Conclusions 8

How power is consumed Servers Cost # of Processors Volume $25, 000 1~2 Mid-range $25, 000 ~ $499, 999 2~4 High-end ≥ $500, 000 ≥ 8 Estimated Average Power Use (W) per Server, by Server Class, 2000 to 2006 (Source: Koomey J 2007 b Estimating Total Power Consumption by Servers in the US and the World. Oakland, CA: Analytics Press) Google container Data Center http: //www. youtube. com/watch? v=z. Rw. PSFp. LX 8 I 9

Total power consumption • Power consumption of a Quadcore Intel Xeon server Server Power Consumption (Source: Intel Labs, 2008) 10

Total power consumption (cont’d) • Power consumption of components Components Power consumption Multi-core CPU 45 ~ 200 w DIMM 5 ~ 21 w Power supply efficiency loss Similar with memory p. s. 2 PCI Slots 50 w 2 ~ 4 Hard drives 24 ~ 48 w 11

Total power consumption (cont’d) • Total power consumption CPU Utilization and Power Consumption (Source: Blackburn 2008) • Estimation of power consumption 12

Memory power consumption • The memory demand is growing in the future, because § More processors on chip, § Increasing use of virtualization, § More memory intensive search applications (Google and Facebook) • The memory power consumption is growing in the future § The more the memories, the larger the power consumption § The faster the memories, the larger the power consumption 13

Memory power consumption (cont’d) • Memory Power Comparison RDIMM Memory Power Comparison (Source: Intel Platform Memory Operation, 2007) 14

Memory power consumption (cont’d) • Power consumption by vendors and configurations RDIMM Power Consumption by Vendor and Configuration (Sources: Publicly-available datasheets from each vendor, 2008) 15

Memory power consumption (cont’d) • 64 GB system power consumption Future DIMM Power Consumption by Frequency, Configuration, and Capacity (Source: Intel Platform Memory Operation, 2008) 16

Memory power consumption (cont’d) • How to reduce memory energy consumption § By doing thermal analysis, embedding thermal sensors and throttling 1 U Server Architecture (Source: Intel Labs, 2006) 17

Memory power consumption (cont’d) • Memory throttling mechanisms § Closed loop thermal throttling (CLTT) • Closed loop, rely on thermal sensors § Open loop throughput throttling (OLTT) • Open loop, work based on bandwidth count • Memory throttling degrades performance 18

Power supply efficiency loss • Power supply efficiency vs. utilization level Server Power Supply Efficiency Test Report (Source: Lawrence Berkeley National Laboratory, 2004) 19

Storage power consumption • Average hard disk power consumption for average operations • Average hard disk power consumption for IO intensive operations 20

Conclusions • High-end servers consume more power, but might be less efficient in terms of power consumption • At present, CPU still consumes the most power, compared to other components • In the future, memory can consume more power than CPU • Considering a significant amount of power loss, the efficiency of power supplies is also very important • The power consumption by hard drives is closely related to the workload the server is processing 21