Testing MySQL on a multicore Mac

Making my Quad G5 Mac work a little harder... Now that it has 4G of RAM, it doesn't seem to swap as much and I can happily build up to 2 MySQL source repositories and a couple of concurrent mysql-test-run.
I am currently experimenting with a RAM drive for handling the test run data, using something like the following for creating a 512M RAM disk.

diskutil eraseVolume UFS RAMDisk `hdid -nomount ram://1048576`
sudo chmod g+rwt /Volumes/RAMDisk

export MTR_BUILD_THREAD=auto
export MTR_MEM=/Volumes/RAMDisk

So far, looks pretty good.