Panasonic S5 II X has a 24.0MP Full frame (35.6 x 23.8 mm ) sized CMOS sensor and features Venus Engine processor. On the other hand, Samsung NX1 has a 28.0MP APS-C (23.5 x 15.7 mm ) sized BSI-CMOS sensor and features DRIMe 5 processor.
Another similarity between these two cameras is that both Samsung NX1 and Panasonic S5 II X sensors lack anti-alias (Low-Pass) filters. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the S5 Mark II X and NX1 sensor size comparison.
Sensor Size and Resolution Comparison image of Panasonic S5 II X and Samsung NX1 Cameras
As seen above, Panasonic S5 II X has a 2.3x Larger sensor area than Samsung NX1. 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.