32-bit applications can only address approximately 4 GB of RAM. The EXS24 mkII can address its own memory space in the 32-bit version of Logic Pro. This enables the EXS24 mkII to use any available RAM in the system— outside the memory used by the application and operating system. You must have at least 5 GB of RAM installed in your computer to use this feature.
The 64-bit version of Logic Pro has virtually no RAM restriction, and automatically addresses all available memory in the system. This enables the use of huge sampler instruments.
Choose Options > Virtual Memory in the EXS24 mkII Parameter window.
In the Virtual Memory window, select the checkbox labeled Active.
In the External Memory Area pop-up menu, choose the required option.
Note: The External Memory Area pop-up menu in the Virtual Memory window is dimmed in the 64-bit version of Logic Pro as the application directly addresses all available RAM. If you have enough physical RAM to hold all the samples for a project, then you will see somewhat better performance by disabling the Active checkbox. In projects with lots of audio tracks playing, and relatively few EXS24 instruments, this may have a noticable effect on performance. If the Active checkbox is disabled, and there is insufficient RAM to hold all samples, then the application will swap data to and from the disk, which will seriously affect performance. Turning off the Active checkbox will also increase project load times, so in most cases, it's best to leave it enabled.
The amount of RAM available for use by the EXS24 mkII is determined by several factors, including:
The amount of physical RAM installed in your computer.
How much RAM other open applications and the operating system are using.
How much RAM Logic Pro is using. This can be affected by the number and size of audio files in the project, and the type of plug-ins used. Sampler or sample player plug-ins not made by Apple, in particular, may significantly affect the amount of RAM that Logic Pro uses.