|thought you guys might be interested in this:
One of the big things that we will be seeing is DirectX 12's Explicit Asynchronous Multi-GPU capabilities. What this means is that the API combines all the different graphics resources in a system and puts them all into one "bucket." It is then left to the game developer to divide the workload up however they see fit, letting different hardware take care of different tasks.
Part of this new feature set that aids multi-GPU configurations is that the frame buffers (GPU memory) won't necessarily need to be mirrored anymore. In older APIs, in order to benefit from multiple GPUs, you'd have the two work together, each one rendering an alternate frame (AFR). This required both to have all of the texture and geometry data in their frame buffers, meaning that despite having two cards with 4 GB of memory, you'd still only have a 4 GB frame buffer.
DirectX 12 will remove the 4 + 4 = 4 idea and will work with a new frame rendering method called SFR, which stands for Split Frame Rendering. Developers will be able to manually, or automatically, divide the texture and geometry data between the GPUs, and all of the GPUs can then work together to work on each frame. Each GPU will then work on a specific portion of the screen, with the number of portions being equivalent to the number of GPUs installed.
We were also told that DirectX 12 will support all of this across multiple GPU architectures, simultaneously. What this means is that Nvidia GeForce GPUs will be able to work in tandem with AMD Radeon GPUs to render the same game – the same frame, even.
This is especially interesting as it allows you to leverage the technology benefits of both of these hardware platforms if you wish to do so. If you like Nvidia's GeForce Experience software and 3D Vision, but you want to use AMD's TrueAudio and FreeSync, chances are you'll be able to do that when DirectX 12 comes around. What will likely happen is that one card will operate as the master card, while the other will be used for additional power.
What we're seeing here is that DirectX 12 is capable of aggregating graphics resources, be that compute or memory, in the most efficient way possible. Don't forget, however, that this isn't only beneficial for systems with multiple discrete desktop GPUs. Laptops with dual-graphics solutions, or systems running an APU and a GPU will be able to benefit too. DirectX 12's aggregation will allow GPUs to work together that today would be completely mismatched, possibly making technologies like SLI and CrossFire obsolete in the future.
Super interesting read (I'd say), but I partially feel that both Nvidia and AMD would refuse to cooperate in a case like this.