Mac desktops represented nearly half of all desktops sold at US retail shops in October, the NPD Group said a new study. About 47.7 percent of desktops were iMacs, Mac minis or Mac Pros, an increase from 45 percent in April and a sharp surge from just 33 percent in October 2008. Mac notebooks also saw a sequential gain from 30 percent in April to 34 percent last month, though this was a drop from 38 percent a year earlier.