Nikon D5600 has a 24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Expeed 4 processor. On the other hand, Samsung NX30 has a 20.0MP APS-C (23.5 x 15.7 mm ) sized CMOS sensor and features DRIMeIV processor.
Another difference between these two cameras is that Nikon D5600's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moire occurring in certain scenes.
Below you can see the D5600 and NX30 sensor size comparison.
Nikon D5600 and Samsung NX30 have almost the same sensor size so none of them has any significant advantage over other in providing control over depth of field when used with same focal length and aperture.
DxOMark Sensor Scores
Both Nikon D5600 and Samsung NX30 sensors have been tested by DxoMark. DxoMark scores camera sensors for color depth (DXO Portrait), dynamic range (DXO Landscape) and low-light sensitivity (DXO Sports), and also gives them an overall score. Of the two cameras that we are comparing, D5600 has scored 84, 7 points higher than NX30.