Global personal computer shipments fell in the first three months of 2014, the eighth straight quarter of decline, although the industry got a boost from companies replacing aging computers, according to two market research firms on Wednesday. Hurt by consumers continuing shift toward tablets and smartphones, PC shipments in the March quarter were down 4.4 percent compared with the same quarter in 2013, IDC said in a news release. Gartner, a rival market research company, said in a news release that PC shipments in the March quarter fell 1.7 percent. The transition to more mobile devices and usage modes is unlikely to stop, although the short-term impact on PC shipments may slow as tablet penetration rises, IDC said.