I'm sure I have seen mine higher when running prime at stock, perhaps just different motherboard BIOS (running MSI) .
I had to give my 1900x 1.3v for 4.1, needs 1.4 for 4.2, temps get a bit high but don't have all the fans on the rads enabled yet, just a test fit make sure everything is working before I add GPUs, hard pipes etc, ram is doing 3600, again needed a touch of voltage above stock, not sure how stable to be honest only done an hour or so of prime as spent most of my time trying to get bubbles out of the bloody Phantek CPU cooler, which seems to have a frustrating air trap in the top corner.....grrr, looks nice though
don't know about DPC stuff, all seems good to me.