I hesitated before doing the noise tests, because I thought I knew how it would turn out. I shot my usual noise test subject with both cameras at f/8, 1/15 second, ISO 3200, manual focusing with the 12x setting:
I processed the images in Lightroom 4.3 with noise reduction turned off, and default sharpening. Then I cropped to the focused upon area, and doubled the resolution using nearest neighbor, thus turning each pixel into a square block of four with identical values.
Here’s the RX-1 crop:
Here’s the NEX-7 crop: