4MB buffer to be exact [0]. [0] https://books.google.com/books?id=K8vUkpOXhN4C&pg=PA950&lpg=PA950&dq=osx+srbk+4mb&source=bl&ots=OLljV-UpVu&sig=n0NaVzZMEBKMk6FP

4MB buffer to be exact [0]. [0] https://books.google.com/books?id=K8vUkpOXhN4C&pg=PA950&lpg=PA950&dq=osx+srbk+4mb&source=bl&ots=OLljV-UpVu&sig=n0NaVzZMEBKMk6FPZAsoOPF6JLo&hl=en&sa=X&ved=0CCgQ6AEwAWoVChMIxJOc7Yy-yAIVzlqICh0v-gov#v=onepage&q=osx%20srbk%204mb&f=false https://books.google.com/books?id=K8vUkpOXhN4C&pg=PA950&lpg=...