JPEG signal to noise ratio
Here we can see that the GM1 competes very closely with other compact system cameras in its category, especially of course the GX7, with which it shares a sensor. It beats the Olympus PEN E-PM2 at the lower end of the chart, being almost identical at higher sensitivities. Interestingly however, it is beaten from ISO 800 onwards by the Sony RX100 II, the compact camera which the GM1 is likely to be marketed against, and which has a much smaller (one-inch) sensor.
Raw signal to noise ratio
The GM1 fares slightly less well for raw signal to noise ratio results. Although it's a consistent performer, putting in almost exactly the same performance as the GX7, it is beaten at every sensitivity by the Sony NEX 3N. From ISO 1600 onwards, it is again beaten by the RX100 II compact camera. At the lower end of the scale however (ISO 200-400), it beats the other cameras in the test.
JPEG dynamic range
In terms of dynamic range, the GM1 is a much more solid performer, putting in a consistent performance across the sensitivities. At the lower end of the scale it closely matches the Olympus E-PM2, before taking over from around ISO 1600. It beats the other cameras on test apart from at the very lowest sensitivity (ISO 200), where the Sony RX100 II and Olympus PEN E-P3 are the winners.
Raw dynamic range
Raw (after conversion to TIFF) performance is very good, beating all of the other cameras at almost every sensitivity. The Olympus PEN E-PM2 does fare slightly better than the GM1 at the very lowest sensitivities of ISO 200 and ISO 400, but they are almost identical at this point.