The CP/M-86 wikipedia page ( https://en.wikipedia.org/wiki/CP/M-86 )lists the IBM PC version release date as 1982-04-05, several months after the Aug 12 1981 IBM PC introduction.

According to this wired.com page, https://www.wired.com/2011/08/0812ibm-5150-personal-computer..., IBM had sold 65K PCs in 4 months.