# Guest Blog: How power consumption and cost calculations work in Configuration Manager 2007 R3

Hey everyone, we have had a lot of interest from you about how ConfigMgr 2007 R3 calculates power consumption, and cost of power since we released R3.  We took these questions and spoke with our Sr. Program Manager Onur Koc, to see if we could publish something that places some clarity around these.   In this post we will cover the first area of understanding Power Consumption calculations, and next week we will publish part 2, Power Cost Calculations.

Thank you to Onur and his team for providing this!

Power Consumption
Below is a typical power consumption report that Administrators might see when the daily power consumption report is run.

• Daily Average Power Consumption by Computer: This graph displays the total daily power consumption reported by devices, divided by the number of devices reporting. Even though the number of devices in a collection changes over time this report will accurately tell if the average power consumption by computers is increasing or decreasing.
• Power Consumption by Day: This graph shows the total daily power consumption calculated from devices that have reported power consumption information.
• Power Consumption Constants: Average power consumption for laptop computers, desktop computers and monitors. These constants can be configured for each report and used in power consumption calculations.

Now that we understand what this report shows, let’s discuss how power consumption is calculated. Data for power consumption reports is calculated based on how long devices in a selected collection are in active, sleep or shutdown states for a given day or month. The ConfigMgr power management agents keep a detailed history for each day for the last 31 days on how many minutes a device is in these states. Monthly power consumption will be the same as daily; it is just that data will be summarized to monthly levels.  Let’s take an example scenario to better illustrate how the calculations works.

Example Scenario:  Company X has 1000 devices as part of power management.

For a selected day, a selected device is ON for 8 hours, in sleep for 15 hours and OFF (shutdown/hibernate) for 1 hour. The ConfigMgr power management agent stores this information and also knows if this device is a laptop or desktop system. Laptop and desktop devices have different average consumption figures which are configurable through report constants. Let’s assume that device is a laptop (no monitor connected by default).

We multiply active and inactive time with average power consumption constants.

 ON state power consumption for the selected device 8 hours x 20 watts per hour 160 watts Sleep state power consumption for the selected device 15 hours x 0 watts per hour 0 watts OFF state power consumption for the selected device 1 hours x 0 watts per hour 0 watts Total power consumption for the selected device 160 watts*

*for selected day for this device
Note: The power consumption difference between SLEEP and OFF (Shutdown/Hibernate) states is virtually zero.

Even though the same power policy is applied, each devices power consumption could be different based on variables such as user activity. At the end, all 1000 devices will report their power consumption through hardware inventory.

As an example – Based on 1000 devices (shown in Power Consumption by Day report).   If the total power consumption calculated is 200,000 watts for the selected day, since 1000 devices reported power consumption information, the average power consumption by computer will be 200,000 watts/1000 = 200 watts per day, which will be shown in the ‘Daily Average Power Consumption by Computer report’.

How to modify power consumption constants

The Administrator can go to the report properties in SQL Server Reporting Services and modify the power consumption constants (Laptop/Desktop/Monitor ON/OFF/Sleep state power consumptions) used in existing power consumption reports. Or, the Administrator can chose to copy an existing report and define different power consumption constants.

Thanks for reading, next week we will follow up with Part 2 on Power Cost Calculations.

Some resources for you:

• Manage, Monitor, and Report: Implementing a Power Management Strategy with System Center Configuration Manager 2007 R3 download