Nikon D3000 High ISO RAW
Nikon D3000 High ISO RAW Image Quality
We've recently started looking at RAW files converted with dcraw, an excellent freeware raw converter. dcraw usually offers timely support for the latest cameras, but more importantly, it does not apply any noise-reduction, sharpening or other corrections such as geometric distortion correction to the output files. (We found that Adobe Camera Raw still applies some limited noise-reduction when its NR settings are set to zero, and it also applies other corrections depending on the make and model of the camera). There will always be differences between RAW converters, in terms of the sort of demosaicing algorithms they use (the processes by which they convert the separate Red, Green, and Blue data sets to an array of full-color RGB pixels), but dcraw seems to use a fairly generic algorithm that delivers good sharpness with relatively few artifacts, and can be counted on to not apply any noise reduction if you don't want it to.
Below are crops from Nikon D3000 high ISO RAW files compared to RAW files from the Canon XS and Sony A230. We chose these models to compare, as they are the entry level models from the top-3 players in the SLR space. The NikonD60 is also included for good measure.
As you can see, the Canon XS still holds the edge in terms of noise in its RAW files. The Nikon D3000 and Sony A230 are very similar (not surprising, since Sony manufactures the Nikon D3000's sensor), with perhaps the Sony being ever so slightly cleaner. It's interesting that the D3000's predecessor, the Nikon D60, seems to be slightly better in terms of noise.