Hi Graham,
Cheers for the help Bud, yeah the 4-component vector of vec4 error was what confused me at that point. Gone through all 30 shaders now and fixed 6-7 other issues that were similar. How come you guys are making the compiler even more strict (far stricter than Nvidia's anyway, being able to mix fx shader code with GL for example). Im guessing it's because Kronos now will only give opengl compliance for drivers that so tightly fit the spec?. Also PS i did a few tests of the opengl insights Massive Number of Shadow-Casting Lights with Layered Rendering code (if you want to test you self the codes on github), in the new drivers not only do you get the above 25% cpu issue but also my FPS drops from 29 FPS with layered rendering enabled to 13.4 FPS compared to even the 13.9 drivers. I can't remember which was the last catalyst that didnt have the 25% cpu usage issue (should be only1-2% CPU) but once AMD drivers page is fixed and show past driver downloads (as at the mo nothing shows on any past driver downloads page) ill track down the last driver that worked which should hopefully allow you guys to track the issue quicker. Cheers again for the help.
James