Path Tracing Sample in the viewport When I activate the shading Rendered in the viewport, the number for path tracing sample keeps going with a single number. The number of the last sample is usually listed but it is not the case in the file I imported from a site. I checked the render settings and the number of samples for the preview is set to 0, the one for the render is set to 55. But the render keeps going for an hour and more. I wonder why.
If you look at tooltip, you will see "unlimited if 0":



So it will render until you stop it.