One thing to consider is we also aren't using small development boxes. These were Power7 zSeries servers with usually 16 cores (8 in hardware) and up to 32GB ram. You would be surprised what these machines are capable of. Of course, I'm not saying I can allocate a gig in .24 seconds and set it to zero, but I'm not saying its not possible either (I simply don't know as I no longer have access to these machines).
