Blender rendering a single tile.

I am not sure what I changed on my settings, I face a prober where blender cycles is rendering my scene with single tile, regardless of the tile size I set in Performances.
Any assistance to solve the issue would be greatly appreciate .
thanks.

You probably checked ‘progressive refine’ checkbox. Render settings, performance, ‘prog refine’ checkbox. Uncheck it.

Photox,
Thanks, that was the problem.
I have rendered my project , what you guys thinks. It is not art but technical. I am having difficulties with sharpness and fireflies


I really like the model, I think the material could use some more gloss.

Thanks, I will add more gloss and see the impact.