The activation of the Variable Refresh Rate (VRR) feature has shown a notable decrease in idle power consumption on AMD Radeon graphics cards, especially when using single or dual high-resolution, high-refresh-rate monitors.
The discovery came after ComputerBase upgraded its labs with Powenetics V2 hardware and software, enabling enhanced power metric logging and incorporating a new 4K display with a 144Hz refresh rate and Adaptive Sync support. This prompted the retesting of all graphics cards, leading to the observation that enabling VRR can significantly reduce idle power draw. Although VRR is available in both Windows and AMD drivers, it cannot be autonomously activated in the latter.
Particularly noteworthy was the Radeon RX 7900 XTX from AMD's RDNA 3 graphics card series, which exhibited the most substantial advantage. It demonstrated 81% and 71% less idle power consumption in single and dual-monitor settings, respectively, compared to its usual operation. Even under practical tests involving Windows movement, the reduction was still significant at 36%. Additionally, enabling HDR during SDR YouTube playback resulted in a substantial 31% decrease in power consumption. Similar behavior was observed in the preceding RDNA 2 series, including the Radeon RX 6800 XT and Radeon RX 6700 XT, although to a lesser extent. For example, VRR activation led to a 79% reduction in the Radeon RX 6800 XT's idle power draw and a 17% decrease during the Windows movement test.
Conversely, enabling VRR on Intel and Nvidia graphics cards resulted in increased idle power consumption. ComputerBase recorded up to 11% higher idle power consumption on the Arc A770 from Intel and up to 25% increase in idle power consumption on a single monitor with Nvidia's GeForce RTX 40-series graphics cards.
Despite the significant improvements in idle power consumption with VRR activation on AMD Radeon graphics cards, the power consumption remained higher compared to Nvidia's GeForce RTX 4080 during Windows movement and YouTube tests, suggesting Nvidia's continued power efficiency.
ComputerBase has reached out to AMD for further technical details on how VRR contributes to the reduced idle power consumption in RDNA 3 graphics cards, and updates will be provided based on the insights received.
