AUSTIN, TX — Notebook PCs demand surged in the second-quarter, with sales of netbooks growing 40% sequentially and notebooks up 22%.

Overall unit sales topped 38 million, according to research firm DisplaySearch.

Netbooks have reached a 22.2% share of the overall notebook PC market. Meanwhile, competition is ramping up as Acer, HP, Dell, Lenovo and Toshiba are steadily gaining on Asus, the market pioneer.