ToastyX’s AMD / ATI Pixel Clock Atikmdag Patcher has long been used to modify AMD / ATI video drivers to provide better performance by removing the 165 MHz clock limit for single-channel DVI and HDMI, the 330 MHz limit for dual-channel DVI, and the 400 MHz limit for VGA Which is useful for everyone who is mining with ATI / AMD GPUs. This tool also has the ability to fix video drivers and remove BIOS signature verification.
There are other solutions that allow you to override the BIOS signature verification, but using the AMD / ATI Pixel Clock Patcher tool is by far the easiest. The current latest version 1.4.7 is compatible with Catalyst 11.9 to Adrenalin 19.9.2, although it can be used with future versions. All you have to do after installing the AMD video driver is to download the tool and run “atikmdag-patcher.exe”, then just reboot.