Do I really have to worry about alignment when using placement new operator?

Question

I read this When should I worry about alignment? but I am still do not know if I have to worry about not aligned pointer returned by placement new operator - like in this e

Answer 1

a quick google tells me that gcc on powerpc has an option to tell the compiler if unaligned accesses are handeled by the system or not.

I would assume that in either case unaligned accesses on that platform will be very slow, and should be avoided as much as possible.