I ran aticonfig --odgc --adapter=all for the rig that drops after a min.
On boot, it's still running at 2.5-2.6 Mh, all 4 GPU's data are the same. eg. core, mem are 1025,1400, bus speed is
5000:

After a few mins it started dropping down to 2.3 Mh. ALL GPU's data remained the same. eg. core, mem are 1025,1400, bus speed is
5000:

So, nothing really changed at all from the GPU's setting perspective....
On my other rig that held steady at 2.77 Mh/s now over 15 hours at this speed, core, mem is the same as my other rig, BUT bus speed is only
2500
Any one know how to set bus speed independently so I can test further to see if that has anything to do with it??