Fujifilm X30 has a 12.0MP 2/3" (8.8 x 6.6 mm ) sized CMOS sensor and features EXR Processor II processor. On the other hand, Olympus E-M1 has a 16.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features TruePIC VII processor.
Below you can see the X30 and E-M1 sensor size comparison.
As seen above, Olympus E-M1 has a 3.9x Larger sensor area than Fujifilm X30. 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.