The performance was about 10 times faster than writing data to a floppy drive.
Such a buffer command can be implemented using system calls for reading and writing data.
Writing data to a tape is often a significantly time-consuming process that may take several hours.
To write data, current is sent through a coil in the head as the media rotates.
In some cases the drive will take two steps to write data rather than one and introduce a delay of about 5 milliseconds.
The problem is, look what happens if you were to ever write too much data in that buffer.
Writing data is slower though, because all disks need to be updated.
This means that writing data is faster, as it can be done in parallel.
Under these circumstances, a "Device full" error would be reported when you tried to write data to the file for the first time.
Eventually, the hard drive will write new data over the area where the old file is located.