yea, sorry about that, just an awful GPU of NVIDIA's.
something like that is not caused by the GPU. It's caused by not giving the system long enough time to render. Even when it is a CPU render you can have good quality renders. If you have an old GPU the render can be still without noise. Just some advice :
Go into the render settings
Set the Max samples to a huge number (10K or more), set the Max Time (secs) to a huge number also. This way the render won't stop because you set a limit to quality manually. Instead, set a Rendering Converged Ratio to something high enough like 98.0% for example (don't set it to 100% or the render would likely never end), and let that percentage decide for you when to stop the render. This value of 98% will make the scene converge to a noise free result on its own without any Time limit or Max Samples influence.
- Even with a high Converged Ratio, there might always be noise in some complex areas (refraction, etc.). Sometimes, it's better to render a whole scene with more simple materials and Spot Render later complex areas : like for your window, you could simply hide the window object with glass shader during the main render to speed it up, then show the glass window and Spot Render that area to get a fast and clean result of that area of that specific part of the image.
This will take a longer time to render. I always render when I don't need the PC. To have a speedy render even with those parameters set high you need a GPU with enough VRAM, because all render that do not fit into the VRAM will be rendered in the RAM with the CPU and that is way slower. That is why I bought a RTX 3060 that has 12GB VRAM and not a RTX 3070 that had 8GB at that time. (A 3080 or 3090 were not in my available budget. Today I would choose a RTX4070ti because of the 12GB VRAM and low power consumption with out that problematic melting Hipower plug)
Another important thing is to check the assets. A background asset does not need high quality. There is for example a very bad package from DAZ with some stationary were every piece only came in 8K. You don't need a pencil in 8k- 512bytes is enough for a pencil. The 8K just eats VRAM you need for more important things like characters. Good tools to use are camera view and scene optimizer. (Each about 25$) Scene optimizer can change the resolution of assets and camera view optimizer can remove all assets than are not in the camera view. No need to load items into VRAM that are behind a wall and it speeds rendering up.
BTW - even with parameters set high you can always stop a render if the quality is good enough for you and save that render. No every render need the 98% converged ratio to look good.