Audio noise and cracks and clicks when using only one proces


when i use the default setting , Option> multicore>OFF in Halion 6 i gat click and cracks in the audio , even if i load only one or two parts .
The problem seems to be fixed when i select multiprocessor option 2 or more . But then it says i might lead to drop out . So is it a good option ? What should i do
I am using a mac pro 2.7 GHZ 12-core intel xeon E5 Memry 64 GB .
Should i select Option>multicore>12 ?

Thanks Patrick Mimran