Competition from flash memory and increased shipment of PCs and consumer electronics are driving down prices and fueling demand for hard disk drives, according to a survey released by iSuppli Wednesday. Average pricing of notebook hard drives tumbled, falling to US$53 in the third quarter of 2007, from $86 in the same period during the previous year. Desktop hard drive prices fell to $51 in the third quarter of 2007, compared to $52.75 the previous year, according to the survey. For the study, prices were measured on a disk basis, not per gigabyte. Overall, about 134 million hard drives shipped in the third quarter of 2007, compared to 114 million the previous year, a 21 percent year on year increase, iSuppli found. Prices also dropped from intense competition between six hard drive vendors: Seagate, Western Digital, Hitachi Global Storage Technologies, Fujitsu, Toshiba and Samsung, said Krishna Chander, senior analyst at iSuppli. Read the full survey here.