Noise at ISO 800

The Olympus OM-D E-M10 has noise at ISO 800. Even the JPGs do. Might need to change the noise reduction setting. I do have Neat Image, which can remove the noise. P2200004 If you zoom into that image, you can see noise on the walls. Why would the OM-D E-M10 have more noise then the E-PM2? Maybe it's just in my room. Noisy wall. Just that picture. The other picture I took in a different room at the same ISO doesn't have any noise.