According to the latest market data findings from ABI Research, total system shipments for portable computing are predicted to reach 165 million units for full-year 2015, essentially flat compared to 2014 levels. Assuming that the free upgrade promotion to Windows 10 OS offered by Microsoft is successful, much of the Windows installed base are likely to use their current computer hardware for at least a while longer.

The portable notebook PC category consists of four segments: netbooks, notebooks, Chromebooks, and ultra-portable PCs. "Segment growth is occurring in Chromebooks, much in part due to purchases by schools," said research director Jeff Orr. "Growth for 2015 is also in ultra-portable PCs where thin and light designs are looking to tackle more mobile use cases by reversing the display panel flat like a tablet or having the screen separate entirely."

Chromebook shipments are expected to increase 35% annually by the end of 2015 to seven million units. Sales led until now by North America educational buyers will yield to purchases in other geographic markets over the next five years, resulting in a 22% CAGR.

Ultra-portable PCs, including 2-in-1 convertible and detachable display models, experienced typical first-quarter seasonality with a 24% drop in on-quarter shipments to 7.2 million units. Apple's MacBook Air continues to lead all ultra-portable PC vendors, though Lenovo and Dell are closing the gap. The balance of the year is expected to remain soft for segment growth.

Notebooks will experience a shipment volume decline of about 7% on year.