If you emphasis on reading comprehension, the actual questions was how many processor cores is need to verify the incoming transactions + the mined block?
Since you asked, I just looked in the log file on a 4-year old Xeon server I'm using as a node. It takes approximately 0.14 seconds from the time a new transaction arrives until the time it is relayed. I believe most if not all of this processing is single threaded, which suggests approximately 7 transactions per second per core on a 4-year old CPU.