Solid-state storage has seen a similar drop in cost per bit. In this case the cost is determined by the "yield", the number of viable chips produced in a unit time. Chips are produced in batches printed on the surface of a single large silicon wafer, which is cut up and non-working samples are discarded. Fabrication has improved yields over time by using larger wafers, and producing wafers with fewer failures. The lower limit on this process is about $1 per completed chip due to packaging and other costs.