With git  "HEAD at ec83535 automake/gallium: attempt to fix -lrt", Cool VL
Viewer a TPV for Second Life 3D world  ( the official Linden Lab viewer is from
ages blocked cause of https://bugs.freedesktop.org/show_bug.cgi?id=39251 ) can
set only basic shaders otherwise with atmospheric, water and reflections
shaders enabled, I have extensive blue triangles  during the execution.
On the contrary with graphics drivers from git-54ff536 ( HyperZ enabled by
default) all was right  with smooth rendering, lowered cpu usage and augmented
framerate ( 8-10 %).