After examining the shader dumps one thing that looks suspicious to me is that in the good dump, we have several instructions like this: image_load v[9:12], 15, 0, 0, 0, 0, 0, 0, 0, v[4:7], s[8:15] But nothing is ever written to the last component of vaddr: v7 However, in the bad dumps we have: image_load v[8:11], 15, 0, 0, 0, 0, 0, 0, 0, v[1:4], s[8:15] And a value is stored in the last component of vaddr: v4 before every image load.