On the Memory cache page, you can configure the memory cache for the Undo and Redo commands, tiling, and the total limit. The total limit is the maximum amount of memory caching available on your system.
Total limit is the sum of the cache of Undo/Redo and Tiling. By adjusting the cache for Undo/Redo, you ensure that the total limit is divided, based on the way you work, between the cache for undoing and redoing, and tiling.
Undo/Redo
The amount of memory available for the Undo and Redo commands. The value you specify is in kilobytes (KB). You can specify up to a maximum of 25,000 KB (25 MB).
For example, when you are burning a shape within a raster image, the previous state of the data is kept in memory. The size of the bounding box of the new shape, in pixels and lines for raster data types, and the number of input channels are all stored temporarily as an undo/redo step. This can use a lot of system memory. The number of undo steps cannot be computed based on the size of the undo/redo cache. Each undo step requires varying amounts of memory.
Clear Undo/Redo cache
Clear all cached data accumulated as a result of applying the Undo and Redocommands.
Tiling
The amount of memory available for raw image inputs and display caching output. The value you specify is in kilobytes (KB).
The larger the data set, the more memory is needed. For example, an 8-bit image measuring 512 pixels by 512 lines requires 1 byte for each pixel, or 1 MB of information for each 8-bit raster layer. With very large files, you can experience memory deficits requiring more memory to display requested data. If the tiling cache is set too low, a system will swap data because it is designed to deallocate and then reallocate memory to stay within the limits of your data.
The tiling cache changes the way you can render an image in the view pane. When you work with very large images, you can increase the memory allocated to tiling, which has a direct impact on rendering. By increasing the size of the tiling cache, the image will render faster.
Clear tiling cache
Clear all cached data created as a result of tiling.
Total limit
The maximum memory allocation. The value you specify is in kilobytes (KB). To allocate all available system memory, enter a value of 0 (zero).
Total limit is the sum of the cache of Undo/Redo and Tiling. If both are set to zero, the limit becomes the total limit for the sum of the two. You can specify, in kilobytes (1024 KB = 1 MB), the limit of memory allocation. When zero is entered, the system allocates one third of system RAM as the total limit of memory cache.
Default memory usage
Reset the cache limit to the default. The default memory usage is one-half of system memory. For example, with a system that has total memory of 500 MB, the cache is reset to 250 MB when you click Default memory usage.
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