Your file is HUGE by SU standards.
Over 23 million edges, almost 14 million faces, file size almost 940MB.
ANY computer will struggle with this large and complex a SU model.
Most of the fabric is over-detailed, with more faces and edges than is needed to render smoothly.
Look at this monochrome view of part of the sofa, with hidden lines visible:
And one of the flower vases:
And too many reversed faces (showing dark blue/gray) including almost all the flower petals here, and the background of the latticework panels in the background .
You could get a model that would render equivalently with FAR fewer edges and face.
That kind of thing is what is slowing down both your modelling in SU and even more, the rendering.
There are some plugins that can help simplify over-detailed geometry, or you could learn to draw them yourself more simply.
Or use the tips in the previous post to simplify your model.
Did you import the components from the 3D warehouse? Many examples there are like this one - vastly over-detailed to no useful purpose. Usable, perhaps, on their own, but too much detail to be readily usable as a small part of a larger model.
Before incorporating them in your model, it is always worth downloading each into a separate SU model, to check if they are over-detailed, and for you to try to simplify or redraw them. Or find less elaborate equivalents.