R GC timing

gc_speed_test.R

library(microbenchmark)

cat(version$major, version$minor)

createdf <- function() { 
  x <- runif(100000)
  y <- runif(100000)
  z <- runif(100000)
  
  df <- data.frame(x = x, y = y, z = z)
  gc()
}

microbenchmark(createdf(), times = 1000)

Results indicate forced GC for each iteration is slower in R 3.5+

3 4.3Unit: milliseconds
       expr      min      lq     mean   median       uq      max neval
 createdf() 14.26464 15.1249 15.94736 15.70314 16.50341 39.91744  1000

3 5.2Unit: milliseconds
       expr      min       lq    mean  median       uq      max neval
 createdf() 22.11165 24.02668 24.6672 24.3578 25.05036 44.39232  1000