1. The output is consistent for all graphics cards that pass the hardware test.
2. Different graphics cards differ mainly in real-time operating performance and rendering output efficiency. To see more statistics for your reference, you can go to Benchmark and see test results from D5 users. You're also welcome to run this tool yourself and see how your hardware ranks alongside others when running D5 Render.
3. Currently, D5 primarily utilizes Dedicated GPU memory and does not support multi-graphics card parallel/interconnected operation. Therefore, it is advisable to keep one graphics card which is at a high level of performance.