Williams, the 113th overall pick out of Boston College, led the nation in rushing, carrying the ball 355 times for a school-record 2,177 yards - 6.1 yards per carry - and 18 touchdowns.
He was a finalist for the Heisman Trophy and won the Doak Walker award as the nation's top running back.
Berhe, the 152nd overall selection, led San Diego State in tackles with 94. He had 60 solo stops and two fumble recoveries. While he didn't have an interception as a senior, he had five over the previous three years.
The Giants with five more draftees to sign.