The movement of the hard drive's read/write heads over different areas of the disk when accessing fragmented files is slower, compared to accessing the entire contents of a non-fragmented file sequentially without moving the read/write heads to seek other fragments.
The giant oceanic manta ray can grow to a disc size of up to 7 m (23 ft) with a weight of about 1,350 kg (2,980 lb) but average size commonly observed is 4.5 m (15 ft). It is dorsoventrally flattened and has large, triangular pectoral fins on either side of the disc.
Both the largest species of this order and the largest of all rays is the manta ray (Manta birostris). This peaceful leviathan can reach a size of 3,000 kg (6,600 lb), a disk width of 9.1 m (30 ft) and a total length of 5 m (16 ft). A related species reaches barely smaller sizes, the devil fish (Mobula mobular).