Power limit and voltage increase causing artifacts

[ar3005000]

I have a MSI r9 390x with the g10 bracket water cooled and heatsinks on both vrms

 

Using Afterburner and I have used Guru3d ddu and completely removed afterburner and flashed the original bios before I ever tried overclocking. Still same results. 

 

On stock voltage and power limit I get artifacts when I increase core clock by 20 mhz 

 

When I have core and memory clock on stock and increase power limit even by 5% I start to get artifacts

 

I cant even overclock 20 mhz on core without artifacts. The GPU temps are fine

 

Anyone got any suggestions to what I could be doing wrong.