The Crux wiki has been getting a facelift recently (not by me of course — I hardly think myself qualified), and one of the gems that has come to the surface is this little monster — how to speed up compilation by building software in memory.
I tried it out yesterday with Leafpad, building one version in a regular directory, and then again with a work directory in memory. On a relatively small program like that (and on a machine with only 512Mb total, which meant only about 256Mb as a tmpfs folder) I got a drop of about three seconds off the old 28-second compilation time.
You can try it yourself and see if the results are improvements for you — use
time prt-get depinst whatever-pkg and you’ll get a breakdown on how long it took to finish the job. Like I said, a small program saw a nice reduction, but you’ll need a lot of memory to compile some of the bigger ones. (I tried to install recorder with the folder in memory, but forgot that it requires cmake for some of the dependencies, which quickly ate up all the space it had.)
So from my perspective, the description in the wiki is fairly accurate — it does cut down on the time it takes to compile, but it also takes quite a bit of space to use that trick. Those of us on older machines might just have to suffer.