rx 480 VDDCI offset vs VDDC?

After many hours I was able to successfully add VDDC and VDDCI offsets to my rom, and can confirm that the VDDC offset at least works, however I can't seem to do anything with VDDCI. Sure I can set an offset of +50mv/100mv but it seem to actually *do* anything(mem can't clock higher, still stuck at ~1925 for shitty hynix). I'm currently undervolted by a quite a bit, so my question is this, is the VDDCI offset bound to the core voltage in any way? ie. does the vddci NEED to be below the vdcc? I can't actually measure the live vddci in linux anywhere, so I have no idea how to test this other than bumping core to 1.1 and then bumping the mclk up and seeing if it's stable.

(I'm currently getting 28mh eth+dcr @ 1130/1925 on a 4gb 480)

Any help would be appreciated!