But more concerning are the cases where AFR is outright incompatible. I touched upon this a bit in our DX12 Ashes article, that games are increasingly using rendering methods that are either inherently AFR incompatible, or at best are so difficult to work around that the development time and/or performance gains aren’t worth it. AFR incompatible games aren’t a new thing, as we’ve certainly had those off and on for years now – but I cannot recall a time where so many major releases were incompatible.
The crux of the issue is that game engines are increasingly using temporal reprojection and similar techniques in one form or another in order to create more advanced effects. The problem with temporal reprojection is, as implied by the name, it requires reusing data from past frames. For a single GPU setup this is no problem and it allows for some interesting effects to be rendered with less of a performance cost than would otherwise be necessary. However this is a critical problem for multi-GPU setups due to the fact that AFR means that while one GPU is still rendering frame X, the other GPU needs to start rendering frame X+1.
