Regarding the 11-yr-old laptop I would be interested to know not only the compile time but also the storage required, e.g. size of src tree plus any tmp space

Regarding the 11-yr-old laptop I would be interested to know not only the compile time but also the storage required, e.g. size of src tree plus any tmp space required, etc. I like to compile kernels using memory-backed filesystem without any persistent storage mounted. This helps with speed. For example, with BSD, I only need about 200 MB RAM to produce a more-than-adequate kernel (about 17 MB). One of the benefits of doing "development" on old hardware IMO is that the programs I write on the old machines is guaranteed to be very fast on the new machines. I can move these programs back and forth between machines without worrying about performance. If I only used new machines to write programs, e.g., small, relatively simple ones, then I could not be sure that they would run well on the older machines.