Monday, July 13, 2009

What's an Exbibyte?

OK, you may be wondering what I'm talking about. What's an Exbibyte? Who cares, right? Forgive me, but I just couldn't help myself. As an MIT graduate, I feel like I should know something about these terms. Allow me to briefly talk about the exbibyte (EB), gigabyte (GB), terabyte (TB), and zettabyte (ZB). I won't even get into megabyte (MB) or kilobyte (KB) in this discussion.

I got onto this topic as I was looking at the maximum file size under different file systems for your computer. When you go to format a hard drive, you can typically choose between FAT 32 and NTFS. Why would you choose one over the other? One of the reasons for me is this: maximum file size.
  • Under FAT 32, the largest file your computer can handle is roughly 4 Gigabytes (abbreviated as GiB or GB).
  • Under NTFS, the largest file is roughly 16 Exbibytes (abbreviated as EB or EiB)
So how big is an exbibyte?
1 exbibyte = 1,073,741,824 gigabytes
Let's look at this another way. A terabyte (TB) is roughly 1,000 gigabytes (GB). We now see hard drives advertised as 1 TB hard drives.
1 exbibyte = 1,048,576 terabytes (or roughly 1 million terabytes)
So, when will we see a 1 EB hard drive?

While we're on this topic, let me also through out another term: zettabyte. Now, does that sound bigger or smaller than an exbibyte?
1 zettabyte = 1 billion terabytes
Where's the limit?


  1. Not to nitpick, but just wanted you to know that it should be NTFS, not NTSF as the FS means file system.

    Also what about the petabyte? That comes next after terabyte, and in a couple of years we should start seeing those drives appear, as we have just barely started exceeding 2 TB drives.

    Finally, if you are using the SI prefixes for storage size, then it would be EB, but if you are using binary prefixes it would be EiB.

  2. Thanks for your comment and for picking up my typos. That's what I get for writing in the middle of the night!