Sony NEX-5R has a
16.0MP APS-C (23.4 x 15.6 mm ) sized CMOS sensor and features Bionz processor. On the other hand, Samsung NX3000 has a
20.0MP APS-C (23.5 x 15.7 mm ) sized CMOS sensor .
Below you can see the NEX-5R and NX3000 sensor size comparison.
Sony NEX-5R and Samsung NX3000 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.