I'm not sure in what way you're using the word "efficiency" here? The research showed that the Go version of the programs were in average faster in terms of ex

I'm not sure in what way you're using the word "efficiency" here? The research showed that the Go version of the programs were in average faster in terms of execution time and consumed less memory than the alternate Lisp versions, yet the Lisp versions consumed less electricity and were thus more energy efficient. So the interesting bit here is that better performance and lower memory consumption doesn't always mean more energy efficient. Now, there is definitely a link between performance and energy use, the research did show that for the most part, faster execution often reflected in lower energy spent, but there were surprising variation within that range where it wasn't always clear cut.