Idle power almost always goes up with higher resolutions and refresh rates [1], and AMD cards typically raise their idle clockspeeds more drastically than Nvidi

Idle power almost always goes up with higher resolutions and refresh rates [1], and AMD cards typically raise their idle clockspeeds more drastically than Nvidia cards [2] when resolution or refresh rate increases. The OP uses an 8K 60Hz screen so 45W seems reasonable. [1] TechPowerUp and ComputerBase have the most thorough collections of power consumption measurements, but compare them to each other and you'll see how much it depends on the test setup. [2] Nvidia's latest 5000 series cards buck this trend. The 9070 XT's direct competitor, the 5070 Ti, has especially high idle consumption for no clear reason.