HP was the No. 1 selling brand for notebooks in the month of April, holding six of the top-10 best-selling notebook model numbers. HP's most popular notebook sold was the EliteBook 9470m with a 1.8GHz Intel i5 processor. The ProBook 4540 line held three of the best-selling product slots for the month as well. Each model in the ProBook 4540 line up has a 15.6-inch display and ranges from 2.4 to 2.5GHz Intel i3 and i5 processors. The ProBook 6570b notebook with a 2.5GHz Intel i5 processor was the 10th best-selling notebook on the market in April.