There's an awful lot of interest around power management in IT and I've been researching this subject in order to see how ZENworks could help ( I'm not talking about the datacentre, it's the end user under the spot light ). My research has made me realize that this is not as straightforward a subject as it seems and there is a polarized view on if it's actually worth the trouble.
Let's start with a few considerations for creating a power management policy.
Ideally users should switch off their PCs at the end of each work day but reality says that a large number do not. So the next best thing is to put them into hibernate mode, dropping the power consumption significantly. Why not switch them off remotely? Because there will always be one or more users that have an application open containing work that hasn't been saved when you remotely power off their computer. And that user will be somebody important creating a career defining moment.
Monitors come back quickly from standby. Therefore put monitors into standby when a short period of inactivity has occurred.
Screen savers consume power. Put the monitor into standby instead with password protection enabled for when it comes back on.
PCs take a long time to resume from hibernation. Sleep is a much better mode to use during work hours with a much shorter recovery time. This avoids annoying end users.
You can conclude from the above that we need two types of power management policy; work hours and all other times. But we haven't answered the question of is it worth it? Well to do that you'll need a process to measure the benefits.
Here's a suggestion:
Obtain data on how much your organisation pays for electricity, normally given in kilowatt hours
Select a random sample of PCs and purchase enough power meters for them ( don't forget the monitors as well ). Try Amazon, other retailers are available.
Use the power meters to obtain the power consumption over a month.
Implement power management policy using the points given above or whatever makes sense for you.
Monitor power consumption again over a month.
Now calculate the savings using figures from steps 1) , 3) and 5). Extrapolate for the entire PC device estate.
Step 6) should show you the savings that could be obtained. If they make sense, implement across the entire organisation. If not, tweak the settings and repeat . Alternatively, don't proceed.
That's it for now. The next blog will show how ZCM and Microsoft's powercfg.exe can be used to implement power management in a Windows environment ( for the linux crowd, and I'm writing this on openSUSE 10.3, you can use powertop from Intel to help. See Less Watts for more information ).