[zeveb]

> as the number starts getting too large, "requests per second" isn't a useful way of measuring the performance of a webserver, you're really more interested in "seconds per request overhead".

There's a similar issue with engine efficiency. Here in the U.S. we tend to measure engines in miles per gallon; the problem is that this isn't (typically) what we care about: we care about cost to drive a distance, not distance per dollar. I understand that in Europe engines are measured in kilometres per liter, which makes more sense. If we measured efficiency here in fluid ounces per mile, we'd see that: a 10 mpg car uses 12.8 ounces per mile; a 12 mpg car uses 10.7 ounces per mile; a 24 mpg car uses 5.33 ounces per mile; and a 36 mpg car uses 3.56 ounces per mile.

[jerf]

While I don't have a link, someone making that point is where I got this idea in the first place. "work units per resource" is a tempting measure because it is mathematically tractable for asking other sorts of questions ("how long will it take me to do 500 work units?", "how much gas to get to Cleveland?"), but for raw benchmarking and understanding purposes "resources per work unit" is often more intuitive as the resource tends towards 0.