I have done 2500 21mpx image reconstruction and it took in normal resolution in about 12 hours. The result model had 360M polygons and there I simplified it to 5M polygon object with 45 8K texture maps. It runs nicely as a VR model.
How ever… When i tried to reconstruct the from same images I had to try it at least 4 times before success… So i guess i was lucky on first time.
Machine i used for reconstruction is Ryzen 1800x + 64G ram + 1080ti + 500G m2.nvme SSD.