I wonder whether someone could give me a tip.
I would like to have a simple drum machine, with about 5-10 5sec long audio samples. This is only going to be a very small part of the patch (sonification), the computer works already on high performance (fans are loud). Now I wonder whether I should import mp3′s or aif files to get the lowest CPU usage and the fastest performance. I guess it will be aif, as it is not compressed, but I am not sure, so I asked.
i second matthew’s reply… AFAIK max (as most DAW apps) decompress mp3 to uncompressed AIFF / WAV.
also it may be worth taking into account the sonic degradation of mp3, depending on whether sound quality is a key factor in your patch. drum sounds have lots of subtle characteristics which can easily be lost in the mp3 encoding process.
There no compelling reason to go anywhere near MP3 files, especially at the length you’re considering – their audio quality is inferior to either WAV or AIFF and you’re adding an extra conversion stage on reading the file using the "import" message.