SANTA CLARA, CA – Apple shipped more than 13.5 million mobile PCs in the second quarter, for 136% year-over-year shipment growth, overtaking HP for the top spot, says DisplaySearch.

Nearly 80% of Apple’s mobile PC shipments were iPads, which reached over 10.7 million units, for 107% year-over-year growth. Apple’s total mobile PC shipments (notebook and tablet PCs) were 3.9 million units more than HP’s nearly 9.7 million units for the quarter.

Tablet PCs continue to be the engine of growth for the mobile PC industry, the firm says. Tablet PC shipments were up nearly 70% sequentially and over 400% year-over-year, with nearly 16.4 million units shipped in the second quarter.

Notebook PC shipments were down 2% sequentially, but up 2% compared to the same quarter last year, with nearly 48 million units shipped during the period.
A consumer notebook PC adoption slowdown continues to hold back the industry following a 2% year-over-year drop in shipments in the first quarter of 2011. Worldwide mobile PC shipments (including notebook and tablet PCs) reached 64.4 million in the second quarter, up 10% sequentially and 28% year-over-year.

Among the top five players, Acer experienced the largest decline in shipment growth, with a 4% sequential drop, and a decline of 12% year-over-year.

In the notebook PC category, Samsung and Dell had the fastest shipment growth, up 44% and 33% year-over-year, respectively. Dell was also up sequentially, with 27% shipment growth, as it continues to take advantage of a rebound in commercial market PC shipments. Samsung’s shipments fell 16% sequentially, as it was unable to build off of strong shipment results in EMEA and China. Still, Samsung was able to top first-quarter shipment levels in North America and Asia Pacific.

Tablet PC shipment results show that even after removing Apple from growth rate calculations, worldwide year-over-year tablet PC shipment growth reached 25%, and shipments of non-Apple tablets reached more than 5.6 million units for the quarter, according to DisplaySearch.