Many AMD end users have expressed frustration at their graphics cards’ core clock “downclocking” below its maximum clock rate while playing games. This shift in clock speed is also often matched with a decrease in frame rate. As a result, many users believe that the reduction in clock speed is the reason for the low frame rate, and become upset.
AMD’s Powertune is a power saving technology that dynamically adjusts the clock rate of the graphics cores as needed, in order to only consume as much power as needed. This way power consumption is lower, meaning less heat is generated, and ultimately means fans don’t need to run as fast, which allows for a silent gaming experience when playing less graphically intensive games such as League of Legends, that don’t stress the GPU.
When an application is met by a bottleneck such as the processor, I/O, or RAM, or an artificial limit such as V-Sync or a FPS cap is hit, the GPU will downclock, as it is not needed 100%, due to waiting for other operations to complete. Most of the time, FPS drops are caused by CPU bottlenecks; however, because the reduced clock speed occurs at the same time(as a result of the bottleneck), it can be very misleading, and cause users to believe the fps drops are caused by the GPU downclocking.
Of course, that doesn’t mean the downclocking is perfect and working as intended. AMD’s Powertune might be downclocking too aggressively, resulting in reduced performance in games or even stuttering, which creates a negative experience. Hopefully AMD will release a driver update or a statement addressing the situation.
In the meantime, you can use a third party utility called ‘clockblocker’ that allows you to lock the core clock of your graphics card to its maximum intended speed. We have not tested this application and cannot guarantee it’s functionality, however most users have reported positive results. Using this application is very similar to disabling core parking in the CPU, as you’re effectively disabling a power saving feature in order to be ensure maximum possible performance.