Both Samsung Galaxy Camera 3G and Pentax X-5 have 1/2.3-inch sized 16.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the Galaxy Camera 3G and X-5 sensor size comparison.
Sensor Size and Resolution Comparison image of Samsung Galaxy Camera 3G and Pentax X-5 Cameras
Samsung Galaxy Camera 3G and Pentax X-5 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.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Samsung Galaxy Camera 3G
or the
Pentax X-5 ,
including hyperfocal distance.