An investor note from Bernstein Research's Toni Sacconaghi has estimated that Apple bought 23 percent of all flash memory made in fall 2011. Going by the estimated storage for each product category and the shipment volumes, he believed that Apple had bought over 1.4 billion gigabytes' worth of NAND flash for storage in the iPad, iPhone, iPod touch, and MacBook Air. In pure parts costs, it may have spent $392 million, he said in Fortune's copy of the note.
