I've noticed that even the most basic Laplace such as for our first test-laplace.R test takes 120 seconds and uses 2.5 GB memory.
That does seem like a lot. Most of the time and memory use is in cc1plus, about 100 seconds of the 120 seconds and most of the memory use. The cpp file for Laplace is 450 KB and the .o file is 80 MB.