Apparently their scheduler isn't. I had an I/O and CPU intensive job running over night on the PowerBook. The system did not run out of memory. But it swapped out sshd, which resulted in the active SSH clients to time out with server does not respond. Which subsequently killed the running job. After six hours.
The next one bragging about how wonderful MacOS X is compared to Linux gets a hit with my PowerBook over the head. At least the hardware is solid.