Both Fujifilm X30 and Olympus SP-600 UZ have 12.0 MP resolution sensors but Fujifilm X30's sensor is 2/3-inch (8.8 x 6.6 mm ) and Olympus SP-600 UZ's sensor is 1/2.3-inch (6.08 x 4.56 mm ).
Since Fujifilm X30's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Olympus SP-600 UZ.
Below you can see the X30 and SP-600 UZ sensor size comparison.
As seen above, Fujifilm X30 has a 2.1x Larger sensor area than Olympus SP-600 UZ. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.