When 32-bit mode is turned on, all samples are loaded into RAM for playback using a 32-bit sample word length. In other words, 32 bits are used to represent each sample instead of 16 or 24 bits (the sample's actual bit depth). This has absolutely no effect whatsoever on how the samples sound, but it saves computer processing resources when the samples are played. The trade-off, however, is that 32-bit mode requires more RAM. If you have plenty of RAM, turning on 32-bit mode can help you gain better performance out of your computer when operating MachFive.