JavaScript：setInterval（）会影响计算速度吗？

I have used Intervals in 2 - 3 places. I am not sure, but, does it really effects the computation speed of java script ? Any body can explain me the concept, if YES or NO, will be help full to optimize my code. I have lots of computation in my code so will be useful if I can optimize. I have used Intervals in 2 - 3 places. I am not