Workflow for big images?

I’ve been working with one quite big image. (25031px wide)

It opens very nicely on Topaz denoise and I can edit the settings. Then I can apply it and Denoise starts processing the image. When it finally reaches 100% the program just crashes and doesn’t give me the output.

Do I need to cut this image into pieces?

How do I edit only an area of the image? If my layer is not 100% of the whole canvas and I open the selected area in Topaz Denoise, I get white color in background which probably doesn’t help with performance, cause the image is still very big.

edit: Ok, I found out that if I make the layers to be smart objects, I can then open the smart object in topaz in a proper way. Not ideal workflow, but at least it’s possible and Topaz didn’t crash with the smaller image.