I have a gaming laptop with an AMD Radeon HD 8970M. I bought this and quickly found out that a lot of games didn't work even though my drivers are fully updated. For about a year there was no updates to fix it and finally an update got released and it made MOST of my games work. After a few months windows 10 was released so I decided to install it. Then I went to play a game that worked with the previous OS (Windows 8.1) I noticed instead of being able to play on Full HD resolution and Ultra graphics I was getting terrible frames while trying to run the game on terrible resolution and lowest graphics. I thought that maybe it was an issue with just that game but no. I checked all the other games and they have terrible Frames also. The only games that seem to run at high frames are the games that the first driver I was using could run and that was a very small amount of games. My laptop easily has the power to run pretty much any game out there on ultra settings. I do not understand why this graphics card always has issues. When you go to buy a high end graphics card you expect it to work on every game and sadly this graphics card only works on a tiny amount of games. To give you an idea of the frame rate between games it does work with and games it doesn't work with ill put some games below showing the insane frame rate differences of games that have equally good graphics.
Call Of Duty: Advanced Warfare - Before: Ultra Graphics Full HD 30-40fps After Windows 10: Lowest Graphics And Terrible Resolution 10-20fps.
Grand Theft Auto V - Before:Best Graphics With Full HD resolution 30-50fps After Windows 10: Really Bad Frames And Having To Run With Lowest Settings 20fps
Survarium - Before: Best Graphics Full HD Very High fps After: A lot of lag
The three games listed above are all very popular games so should work with a massive variety of GPU's.
There are far more games that could be listed here but that was just quickly thinking.
I also downloaded the latest AMD Catalyst and GPU drivers that are supposed to fully support Windows 10 and doing that made no difference.