It's about as much as Watson.
(data store only)
It's about three-fifths as much as a Gap, Inc. Customer Database.
In other words, the amount of a Gap, Inc. Customer Database is 2 times 4,100 gigabytes.(a.k.a. The GAP Companies, a.k.a. Gap) (2012 figures)
The GAP Inc., the corporate parent of GAP store, Old Navy, and Banana Republic, has accumulated over 7,000 gigabytes of data on almost a billion customers. The GAP, Inc remains the largest apparel retailer in the United States and was the largest in the world from the mid-1990s until about 2008.
It's about one-tenth as much as The Amazon.com's databases.
In other words, 4,100 gigabytes is 0.0946206 times the amount of The Amazon.com's databases, and the amount of The Amazon.com's databases is 10.5685 times that amount.(largest databases only; 2005 figures)
It's about one-twentieth as much as The Google Earth database.
In other words, 4,100 gigabytes is 0.0568 times the amount of The Google Earth database, and the amount of The Google Earth database is 17.6 times that amount.(2006 figures) (raw imagery and indexes storage)
It's about one-twenty-fifth as much as The LHC Data Generated per Second.
In other words, the amount of The LHC Data Generated per Second is 30 times 4,100 gigabytes.(a.k.a. Large Hadron Collider) (2008 figures)
It's about thirty times as much as an iPod.
In other words, 4,100 gigabytes is 25.6 times the amount of an iPod, and the amount of an iPod is 0.0391 times that amount.(a.k.a. Apple iPod) (2010 figures; for iPod classic, sixth generation)
It's about one-thirtieth as much as The Hubble Telescope.
In other words, the amount of The Hubble Telescope is 31 times 4,100 gigabytes.(a.k.a. Hubble Space Telescope, a.k.a. HST) (2008 figures)