Is there a driver update for AMD Radeon HD 6770M following upgrade to OSX High Sierra to address the GPU performance issue users are seeing?

Is there a driver update for AMD Radeon HD 6770M following upgrade to OSX High Sierra to address the GPU performance issue users are seeing?

From the point I upgraded to OSX High Sierra it was clear that the GPU was struggling - AMD Radeon HD 6770M 512MB. It coincided exactly with the upgrade. I see other posts on other sites indicating the same behaviour. On previous upgrades where this has happened Apple updated the firmware fro the GPU's - are there any plans to do this in this occasion.

iMac (21.5-inch, Mid 2011)

2.7 GHz Intel Core i5

AMD Radeon HD 6770M 512 MB