buffer index~ slow while reading peak~?

Hi,

Why is it not possible to read peak~ and index~ at the same time from a buffer?

Im reading peak quite fast to get out the values of a buffer. However, It seems to read peak~ and index~ the buffer at the same time, there is a lockup.

Is there any way to avoid this?

Do you think the best way might be to copy to another buffer, while Im reading peak?