The easiest option is probably to render it in a path tracer like Blender Cycles if you want it to look realistic. The problem with opening large LEGO models in realtime rendering programs like others mentioned is all the geometry. Doubling the amount of geometry means your graphics card has to do about double the work. Doubling the geometry in a ray tracer or path tracer like cycles only adds a little bit of extra work since it's not actually rendering the scene triangle by triangle. I would still expect a 3D viewport render to always be faster than a Cycles render. The rendered Cycles viewport in Blender can sometimes be more responsive than a traditional 3D viewport since it doesn't need to render out complete frames.
Cycles isn't the fastest renderer, so you may have better luck in Blender with something that runs in realtime like Eevee. It depends on what quality you want in terms of lighting and material accuracy.
You can try installing the latest version of Blender and importing the model using the new importer linked below. It should easily handle 150000 pieces if you enable the instance on faces option when importing. I've been able to import and render Datsville (400000+ pieces) without any issues. From my experience, large scenes import into Blender faster than opening in LDView, LeoCAD, etc. This is the first release, so there may be some issues like not being able to load some files. Please let me know if you run into any problems.
https://github.com/ScanMountGoat/ldr_tools_blender
Cycles isn't the fastest renderer, so you may have better luck in Blender with something that runs in realtime like Eevee. It depends on what quality you want in terms of lighting and material accuracy.
You can try installing the latest version of Blender and importing the model using the new importer linked below. It should easily handle 150000 pieces if you enable the instance on faces option when importing. I've been able to import and render Datsville (400000+ pieces) without any issues. From my experience, large scenes import into Blender faster than opening in LDView, LeoCAD, etc. This is the first release, so there may be some issues like not being able to load some files. Please let me know if you run into any problems.
https://github.com/ScanMountGoat/ldr_tools_blender