Convert yottabyte to gibibit

The SI prefixes count in thousands: 1 kB = 1,000 bytes, 1 GB = 10⁹ bytes. Computers count in powers of two, and for those the IEC prefixes exist: 1 KiB = 1,024 bytes, 1 GiB = 2³⁰ = 1,073,741,824 bytes, about 7 % more. Disk and memory-card makers use the decimal units, most operating systems display the binary ones (Windows labels them 'GB' regardless), which is why a '1 TB' drive shows as 931 GB: 10¹² bytes is 931 GiB. Nothing is missing. RAM is the exception and is always sold in binary sizes: 16 GB of RAM really is 16 GiB.