Issue with Dell Inspiron 5537 Laptop AMD Radeon HD 8670M Graphics Card

My Dell Inspiron 15R 5537 have a dedicated graphics card of AMD Radeon HD 8670M along with integrated Intel HD Graphics 4400. The laptop is installed with Windows 8.1 64 bit OS.

When I checked Windows experience Index, my graphics performance score was rated low, ie 4.6. I have checked on Internet and found similar problems all over the net and some of them have solved the issue by updating the AMD graphics driver. I checked on Dell website and found that Dell provided driver is old and AMD has the latest driver.

So I installed latest driver from AMD website and my driver got upgraded successfully. But my laptop lost its ability to wake up from Sleep and hybernation after this update. So I rolled back the driver to Dell provided one and wake up function worked fine.

Now, my laptop have the graphics score of 4.6 because Dell has not updated their driver. Also laptop seems to be only using integrated graphics (check in dxdiag) and not using dedicated graphics card even though drivers are installed correctly. What is the need of dedicated card, if we cannot use it? What a waste of money!