As of Play Software update v1.0.46, you are now able to load Play instruments outside of your host sequencer's RAM allotment (which is typically around 4GB) on Mac OS X Tiger and Leopard. There are a few requirements to do this successfully:

-You must be on either Tiger or Leopard

-Your Mac must have a 64-bit processor (G5, or Core 2 Duo or later)

-You would need over 4GB of Ram (8GB or more recommended)

When you load an instrument and leave it set to "Stream From Disk" from Play's Main menu/current instrument menu, it will always utilize part of the host's RAM allotment. To load the instrument outside of your host's RAM allotment, you need to uncheck the "Stream From Disk" option, which will load the instrument into RAM outside of your host. This of course loads larger than streaming, but it will load outside of your host's RAM allotment, allowing you to utilize all of your system's memory.

We recommend loading up Play into multiple instances inside your host and set them to "Stream From Disk" until you are nearing the limit of your host's RAM allotment, for which we don't recommend going over 3GB for stability reasons (you can verify this in the Activity Monitor utility). Once you are nearing this 3GB limit, start opening new instances and load the rest of your instruments into RAM by unchecking the "Stream From Disk" setting.