[Warner306]

4K display
windows 10; Kodi using DS Player/madvr

Am i correct in saying the video card should be expected to work it's hardest when the source is 480i video and work its least when the source is 4K?

If the source is 480i30 (DVD), it would become 480p24 after IVTC, film-based deinterlacing and would be an easier load compared to 4K because a 4K source has more pixels and a bit depth of 10-bits, and chroma upscaling alone is more taxing.

If the source is 480i60 (SD TV), it would become 480p60 after video-based deinterlacing and would be a hard load on the GPU because rendering times would have to be under 16ms.

In general, the most difficult upscales to 4K are 720p and 1080p. A 720p source is usually doubled and then downscaled, which requires the most processing.