Most are 7016 X 2480, the reason for that is they were created with a A4 lay flat photobook in mind which allows the render to cover a two page spread, i just have to be careful what detail in in the centre of the render.  Here the renders are reduced in size and converted to .jpg

Here is a full sized .PNG file as an example.

 

 

I use Poser 13 on Windows 11 - For Scene set up I use a Geekcom A5 -  Ryzen 9 5900HX, with 64 gig ram and 3 TB  storage, mini PC with final rendering done on normal sized desktop using an AMD Ryzen Threadipper 1950X CPU, Corsair Hydro H100i CPU cooler, 3XS EVGA GTX 1080i SC with 11g Ram, 4 X 16gig Corsair DDR4 Ram and a Corsair RM 100 PSU .   The desktop is in a remote location with rendering done via Queue Manager which gives me a clearer desktop and quieter computer room.