Yeah, in that case Assembly/C is the greenest language but should we switch to them?
> The inefficiencies from extra human time would likely offset any potential gains from the pennies you'd save on CPU costs.
I'm not sure I follow what you mean here.
The point isn't about the absolute numbers, it's just trying to illustrate that the numbers are so small that it might as well be a rounding error unless you're talking about industry or society-levels of impact, which Clojure does not really have.
That's just wrong. Electricity used by data centers today add up to the whole consumption of a largish country.
If you can save even just 5% of that, it's an enormous difference. Companies like Google and Netflix spend millions to save much less than that in computing.
But no, that's not how it works at all. Nearly half (about 40%)[^1] of datacenter's total power draw on average is from cooling, which is usually shared across every server in the datacenter. Next, about 30%[^2] of the average server's power draw comes from its CPU (this obviously varies, even at different times on the same server), most servers sit at about 50% utilization on average. So already we're looking at 50% of 30% of 60% = 9% total of energy consumption going to the CPU with very rough, over-estimations.
Now Clojure makes up about 1.25% of code, ish[^3]. Let's round that up to 1.5% to be generous. So a reeeeally rough estimate has Clojure code taking up 0.135% of total datacenter power usage globally assuming averages for pretty much everything. I had trouble finding benchmarks for Clojure vs. Common Lisp, but Clojure is basically just Java at runtime, so this[^3] will do. Benchmarks are kinda silly, but we're talking about really average performance. The benchmarks I could find had Java beating SBCL on most benchmarks, but let's say you stand to gain a generous 20% efficiency by using SBCL over Java. That leaves you at a 0.027% gain in efficiency with a lot of generous rounding and assumptions.
Now, of course most code is not CPU constrained... you get the idea. The efficiency gains are not much at all.
[^1]: https://davidmytton.blog/how-much-energy-do-data-centers-use...
[^2]: https://www.researchgate.net/publication/355862079_A_Review_...
[^3]: https://benchmarksgame-team.pages.debian.net/benchmarksgame/...
A human who spends his day writing code is going to consume (at worst) the exact same amount of food as if he spent only half his day coding and the other half on something else. He might even consume less food while coding, if his non-coding activity is something physically intensive (i.e. burns more calories). I don't really see how the implication (that saving human time saves energy too) can possibly be true.
We've not switched away.
