I have a PC with an AMD Ryzen 5 1600x CPU (6 cores, 12 threads) running Windows 10.
When I use the Adobe DNG Converter, CPU utilisation ranges from 14 to 32%, but never goes above 32. Is there a way to get the DNG converter to use all cores?
Converting a large number of files should lend itself well to parallelisation, because the conversion of each file is totally independent of the converison of the others, so it should be quite straightforward to divide the total files across the available cores.
The DNG converter is a free utility that is quite straightforward in what it does. To my knowledge, there isn't any provision for tweaking it to optimize its performance. You might ask your question in this forum where the Adobe developers monitor more closely. You might get an answer. But I suspect you will find that the DNG converter is what it is and you will just have to be patient and let it do it's thing.