Denoising

Pretty much since it became available, I’ve used GPU rendering exclusively, and I found it predictable. With denoising on, once all four sides of a tile (including perimeter tiles) were rendered, the enclosed one would denoise before the render continued. Single GPU.

Since my new build, with 8 cores/16 threads CPU, and the fact it performs better with some renders, I’m switching to the faster option. However, the denoising is less predictable. It will, broadly, follow the same pattern, but seems to take a “when I get around to it” attitude to denoising. i.e. It no longer prioritises denoising of fully enclosed tiles, but will prioritise them when it gets around to it.

Is this just temperament, or did I lose something in my understanding?