Beck was recruited as a receiver for Cal Poly, but ended up appearing in 10 games as a middle linebacker as a freshman. He earned All-Independent honors in 2001, as he led the team with 73 tackles (48 solo), including 2½ sacks and seven stops for losses. He was again an All-Independent pick at middle linebacker in 2002 after posting a team-high 113 tackles (62 solo), 4½ sacks and 13 stops behind the line of scrimmage.
Beck was Independent Defensive Player of the Year after registering 128 tackles (68 solo) with four sacks, 13 stops for losses, a 41-yard fumble recovery and four pass break-ups in 2003. The middle linebacker experimented at the rover position during the 2004 preseason and also saw action there during the course of the year.
Last fall proved to be a banner season for Beck, as he was a consensus All-American, unanimous All-Great West Conference and Defensive Player of the Year and recipient of the Buck Buchanan Award, given to the top defender in the NCAA Division I-AA ranks. He led the team in tackles for the fourth straight year with 135 (97 solo) and had 5½ sacks, 18½ stops for losses, six forced fumbles, four interceptions and nine pass deflections. His 135 tackles ranked fourth in the nation and his 18½ stops behind the line of scrimmage ranked seventh.
In 43 games at Cal Poly, Beck collected 449 tackles (270 solo) with 16½ sacks for minus-133 yards, 51½ stops for losses of 196 yards, three fumble recoveries (two returned for touchdowns), six forced fumbles, four interceptions for 108 yards with two scores and 16 pass deflections. His 449 tackles set a school career record, shattering the previous mark of 326 by Gary Swanson (1981-84).