Minim very high on CPU when loading lots of sample

Hi, I develop a program on a i7 (quad core). This program load a lots of short sounds (around 500) in minim AudioSample[] with minim.loadSample. No pb here, CPU stay around 30%. But I need to run it on a i5 (dual core), but here CPU get very high (100%...). I thougth using minim.loadSample load sound in RAM, I don't get why CPU go so high. Is there a more efficient way to load/play these samples? Use Sampler array instead of AudioSample array? I try aswell to change the buffer size, some improvements, but not enough... Any help would be appreciate, thanks! Adrien