DX12 and VRAM stacking.

So I'm trying look up more on this VRAM stacking that DX12 will allow. And most of what I find is that instead of letting the GPU rendering alternate frames as they do now, they will be able to render half the frame each. Thus the VRAM on the GPUs are no longer mirroring each other, but hold different information. Naturally the devs also will have to optimize for it.

Do you think devs will optimize for it? Or will be one thing that only a few games will support?

Each frame will be divided up by the number of similar GPUs you have. This known as Split Frame Rendering.

• Will it be used by developers? I think so. It has so many pros and very little cons that it would be silly not to support it.

You can force AFR into games and theoretically, it should work. But we all know that a lot of times, it doesn't work at all or works but with issues. In these cases, AMD and Nvidia work with the developers to get a AFR method working with the game.

With SFR, there should be less trouble since most of the work is on the developer's and their engine. Nvidia and AMD don't have to release a game profile every time a game has multi-GPU issues.

All we have to do is demand the developers to put the feature in the game/game engine.

Here is another pro to SFR over AFR;

Radeon 295x2 running with SFR with Mantle on Civ: Beyond Earth compared to that same 295x2 running with AFR with DX11.

Those steady frame times.

I am not sure, but I think its already inside DX12.

The devs will have nothing to do with it.

Same happens if you want to use a GTX680, a GTX970 and an R9 390 with DX12.

It will see just one GPU with 7200 cores and 10GB VRAM.

Now what would drivers have to do with it then? I guess it will still be driver depended on how well each GPU works.

What won't be supported much is, Cross-IHV multi-GPU. That is a complete headache.

The developers would have to program the engine to assign workloads, in a efficient matter, to different GPUs depending on their powerness. Yeah, way too many factors.

It seems pain in da @ss, true.

But I think its a problem that an engine (cry engine, unreal, frostbite) has to solve, not the game devs.

So if they update their engines to support it, I don't see why the game devs will not use the updated engine.

Still requires the engine to support SFR.

It will theoretically look like it is big GPU, as long as SFR is used.

Neither do I expect them to support that.

@ShadowDeathX said:

Each frame will be divided up by the number of similar GPUs you have. This known as Split Frame Rendering.

• Will it be used by developers? I think so. It has so many pros and very little cons that it would be silly not to support it.

You can force AFR into games and theoretically, it should work. But we all know that a lot of times, it doesn't work at all or works but with issues. In these cases, AMD and Nvidia work with the developers to get a AFR method working with the game.

With SFR, there should be less trouble since most of the work is on the developer's and their engine. Nvidia and AMD don't have to release a game profile every time a game has multi-GPU issues.

All we have to do is demand the developers to put the feature in the game/game engine.

Here is another pro to SFR over AFR;

Radeon 295x2 running with SFR with Mantle on Civ: Beyond Earth compared to that same 295x2 running with AFR with DX11.

Those steady frame times.

That looks nice! I bet AMD will benefit more from this than nVidia. As a user I'm happy to see improvements regardless.

Do you really think devs will take their time to do this? I mean not many uses multi GPU set-ups. I guess partly because of the problems with them, although they have become fewer and fewer. I really want to see this implemented on a wide basis. I'm really thinking about getting two GPU when I upgrade. Then I won't have to worry much about settings I use while playing even though I play at an odd high res.