300 IV per song? Yamaha Psr 970 and A3000

Hi, I'm thinking of buying an A3000 , primarily for world instruments, rhythms and recording. I saw in the specs for the 970 and A3000 "300kilobytes per song" in the recording section. My compositions can be more than fifteen minutes with up to 16 tracks. This is a deal breaker if these keyboards lack sufficient memory. Appreciate any info on this subject. Thanks!