Dear abdul,
I have similar type of system like you , more to CDR data every seconds , my program did update,select and now it moves to 5 millions no purge, all that 5 millions in 1 table.
Try indexing or check your program code, how the transacntion to database is going on, if you do have program codes
That is how we manage it here, it comes from the code, we redesign our codes to make it fast.
We use MyIsam