Just updated my Radeon driver to 11.9 for a few days.
My impression from the overall result of the new driver is more or less the same as when I did the 11.8 update — no obvious increase in fps but feel a little bit smoother. Seems like the driver is getting better every time it updates. Maybe it is psychological since no direct comparison could be made. Anyway, don’t see any performance hit either.
Settings for the 11.9 driver remain unchanged as in 11.8.
Read some posts reporting the drop in fps after the 11.9 udpate. No idea what causes the issue but Rebuilding the Shader Cache may help.
In particular for driver updates, I will beforehand backup both my Windows drive and FSX drive (using Acronis True Image) just in case. This saved me several times in the past.