[1]https://www.pcgamer.com/you-could-fit-the-data-from-25-million-1tb-ssds-on-th
is-5cm-diamond-wafer/

   Researchers in Japan say they've concocted a new method of creating
   wafers out of diamonds able to store mammoth amounts of data on them.
   We're talking 25 exabytes of storage, which is a 25,000 petabytes. Or
   25,000,000 terabytes. Or 25 billion gigabytes. It's a dizzying amount
   of data, that's for sure

References

   1. https://www.pcgamer.com/you-could-fit-the-data-from-25-million-1tb-ssds-on-this-5cm-diamond-wafer/