Truly depends on the strain, but quite honestly, there are folks who grow six (6) plants in a 2x2 tent perpetual who cull 3 oz per grow cycle under 150W HPS. As soon as one plant comes out, there's another around Day 21 who has just shown sex ready to replace the female being chopped.
12/12 on a "small scale" is only for people looking for personal consumption. The yields are medium. However, it's an endless supply of dank. To each his own.