Sony HX9V has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features BIONZ processor. On the other hand, Sony RX100 has a
20.0MP 1-inch (13.2 x 8.8 mm ) sized CMOS sensor .
Below you can see the HX9V and RX100 sensor size comparison.
As seen above, Sony RX100 has a 4.1x Larger sensor area than Sony HX9V. 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.