Memory Requirements

As an image acquisition and display program, Revolution can have extreme memory requirements. On the Mac, the default memory allocation is 8 Megabytes. Windows will dynamically allocate more memory as needed, but doing so may make it less obvious to a PC user if memory is too low for proper performance. In other words, either platform may need a large amount of additional physical memory to run Revolution well.

Because Revolution has the capability to layer objects within images, and for smooth video operation, it currently operates by using one on-screen buffer and two off-screen buffers. This may change as the programmers investigate different ways to store the imaging information, but at present it requires three times as much memory to be allocated as is needed to store just the image(s) the user sees on screen. In addition, the memory must be allocated for preview and acquired images separately. If your memory requirements are tight, we recommend that you select small previews, and save the acquired images to disk and autoclose the screen captures to maintain sufficient memory reserve.

As an example, to acquire a single 4096 x 4096 image at an 8 bit depth requires 4096x4096x3 = 49 Megabytes. A 16-bit image of this nature would require 98 Megabytes. This is just for the image. The program itself and any previews require additional memory in reserve.

Be sure to perform back of the envelope calculations before extensive attempts to acquire large images. Revolution should warn the user if memory is not available, but the program is presently still in beta and there may be memory allocation bugs that 4pi is not aware of.