[maccard]

Both lots and none at the same time. The engines definitely make decisions for you but with unreal (for example) you can modify the RDG any way you see fit.

The problem is that when you need something in gpu you have to go through RAM first (unless you have DMA which is a more recent addition). That doesn’t just add latency it also adds an extra step of cache invalidation, so you have to plan for that from the highest level of gameplay. If you need to prepare for a GPU memory miss _and_ a CPU memory miss as a worst case all the time, it’s very hard to make good use of the bandwidth in the best case