Measuring and analyzing the energy use of enterprise computing systems Xiuming Zhang
Apr 01, 2015
Measuring and analyzing the energy use of enterprise computing systems
Xiuming Zhang
System Deployment
• Powernet: a hybrid sensor network that monitors the power and utilization of the IT systems in a large academic building
• Over more than two years• 250+individual computing devices• One power meter per device
Appliance Types Measured
Extrapolating to the Whole Building
Power Share by Type
• 4 types: PC, LCD, server, switch
PC
• Binned into 3 categories– Laptops– Low-end– High-end
• 742 in total– 456: description available. The other: assume same distribution.
LCD
LCD
• Lower brightness & use dark backgrounds
Server
• Monitors 32 of the 500 servers• Calculated average power: 233 W • Estimated total power of 500 servers: 117 kW
Switch
Switch
PC CPU Utilization
• 95% of the computers have a utilization rate lower than 30%
Popular Workloads
Network Switch Utilization
• The demand never exceeded 200 Mbps
Network Switch Utilization
• Highly underutilized• Total network demand < 1000 Mbps 100% of
the time.
Discussions
How does the sampling frequency affect what the data reveal?
• Too small hide the anomalies
How big is the variance between two instances of same model?
Does sampling a few devices provide an accurate average measurement?
shows the wide distribution of desktop power
Does sampling a few devices provide an accurate average measurement?
• Large sample size desired for PC• 1,000,000 random samples of size 5, 10, and 20, drawing from 69 machines
Do short-term measurements accurately reflect long-term power draw?
• One-month scale yields an acceptable error
Are Energy Star data representative?
• Energy Star Standard does not consider PCs under load
Thanks for the attention!