Interesting blog post and use case for Sankey diagrams by Dr. Ulrich Sigmund at the ANKHOR Feel Your Data Flow blog. He visualizes compiler file sizes using Sankey diagrams.

I am not an expert at this. But apparently 1 pixel in a Sankey arrow represents 400.00 Bytes being handled by a compiler.

In the above simple pic the main chunk of data is code from the SDK directly.

In the next diagram there are intermediate steps. There are objects from the SDK, but also a fair amount created from project files. They are used to create libraries and finally to compile the product. The bright blue arrow is debug info collected during the build process.

Ulrich concludes: “The Sankey diagrams do not only show why your hard drive is cluttered with intermediate files, they also helped me spot some fragilities in the build process. Sometimes the build order was not 100% correct and some of the intermediate files ended up in the wrong folders (due to the fact that the projects have been moved through five generations of Visual Studio by now).”

Any IT guys following here to comment whether this is helpful?

The 2007/2008 White Paper #154 Rev 1 published by APC explains “Electrical Efficiency Measurements for Data Centers”. The author points out that DCIE (Data Center Infrastructure Efficiency), defined as ‘IT Load Power’ divided by ‘Total Data Center Input Power’ is a good metric to analyse data center efficiency.

In fact, as can be seen from the Sankey diagram shown in the paper, the majority of electrical energy consumed in a data center is for cooling, UPS and other supporting infrastructure equipment.

No typical DCIE is given, but the samples shown suggest that it ranges between 30 and 50 %. Several constraints have an impact on the actual DCIE, such as the IT load itself and the outside temperature, and thus should be reported along with the measurement.

A nice idea to present the breakdown on electricity consumption as a Sankey diagram, rather than as a (boring?) pie chart, especially when speaking of “power flows”.

Download the WP #154 from APC’s website.