I too have had a number of CPU spike issues. Basically, I've just purchased cubasis to run on my iPad Mini. I've also got Audiobus installed and a host of other apps with work with it.
But, without starting up audiobus or any other app, if I start up Cubasis, then go and hit the media button, and hit the 'On and On' demo entry, it gives me a prompt to create a new project from the demo.
I enter a new name and then load it up, if I do nothing but play this demo song, I can see that the CPU is constantly up in the 65-75% range immediately, although I do not get any stuttering.
However, when the song gets to bar 57 the stuttering starts and gets so bad that the song almost stops playing until just after bar 73.
So, there is no audiobus, no nothing really, apart from Cubasis, but it can't handle the demo song. Is this just that the iPAD Mini can't handle cubasis or am I missing something out here?
I know you previously mentioned the number of buffers is approx 256, but there doesn't seem to be anywhere that I can adjust or do anything to help reduce stuttering.
I run other apps like Nanostudio with all 16 synths/TRG drums machines running and never get anywhere near 50% let alone stuttering.