AMD has a cross fire api

[monstercameron]

http://gpuopen.com/amd-crossfire-api/

http://gpuopen-librariesandsdks.github.io/doc/AMD-CrossFire-guide-for-Direct3D11-applications.pdf

Alternate Frame Rendering (AFR) is the method used to take advantage of Multiple GPUs in DirectX® 11 and OpenGL® applications. The Crossfire guide describes AFR and how it is implemented in AMD drivers. The guide also provides recommendations on how to optimize a game engine to fully exploit AFR. As described in the guide the goal is to avoid inter-frame dependencies and resource transfers between GPUs. Transfers are initiated by the driver whenever it determines that a GPU has a stale resource. Transfers go through the PCI Express® bus and this is usually an expensive operation.

The Crossfire guide describes the limitations of the default AFR implementation. In summary:

The driver does not know what resources need tracking. It therefore tracks all of them by default.
The driver does not have knowledge of what region in a resource is updated. If a resource is stale all of it will be transferred.
The driver has to start the transfer at the end of the frame even if the resource is only used at the beginning of the frame.
The driver uses heuristics to detect if a resource is stale. The heuristics can fail resulting in rendering artifacts.

 

[digitaldurandal]

Their commitment to open standards and transparency is great. I wish that they got rewarded for it more.

 

[Mercennarius]

Their commitment to open standards and transparency is great. I wish that they got rewarded for it more.

Agreed.

 

[Bacon1]

Very cool, more docs for devs the better.

 

[Kenmitch]

Very cool, more docs for devs the better.

I tend to agree for the most part. It's beneficial to show how to do it correctly. Let's just hope in the end being open about the architecture is beneficial.

Too much info also can be used to expose weaknesses that could be exploited in times of need.

 

[Silverforce11]

Small time indie titles don't have multi-GPU. Big AAA studios are making fast PC ports, they are not going to go the extra mile adding multi-GPU support for the small minority unless AMD sends them engineers to do it or $$ to help lubricate the process.

Putting this out there and hoping studios will do it automatically is... pointless.

 

[Bacon1]

Small time indie titles don't have multi-GPU. Big AAA studios are making fast PC ports, they are not going to go the extra mile adding multi-GPU support for the small minority unless AMD sends them engineers to do it or $$ to help lubricate the process.

Putting this out there and hoping studios will do it automatically is... pointless.

Its not much work for the developers if you look at the API, its basically just few extra parameters to tell the drivers more information about what its rendering so it can know if it needs to send that information to the other card or not.

 

[airfathaaaaa]

Small time indie titles don't have multi-GPU. Big AAA studios are making fast PC ports, they are not going to go the extra mile adding multi-GPU support for the small minority unless AMD sends them engineers to do it or $$ to help lubricate the process.

Putting this out there and hoping studios will do it automatically is... pointless.

they are going very very "stealthy" in all areas..
http://www.overclock3d.net/articles/gpu_displays/leslie_pirritano_moves_from_nvidia_to_amd/1

we only learned because she said so on linkedin amd never did say something

 

[railven]

Small time indie titles don't have multi-GPU. Big AAA studios are making fast PC ports, they are not going to go the extra mile adding multi-GPU support for the small minority unless AMD sends them engineers to do it or $$ to help lubricate the process.

Putting this out there and hoping studios will do it automatically is... pointless.

Good summation. EDIT: Ties to my comment about AMD missing oppurtunities. This is the kind of news/info you want to release with your DMA technology, you know when you're riding high on the multi-GPU. NOT at the end of essentially DX11 where it seems this will help you little as you push DX12.

they are going very very "stealthy" in all areas..
http://www.overclock3d.net/articles/gpu_displays/leslie_pirritano_moves_from_nvidia_to_amd/1

we only learned because she said so on linkedin amd never did say something

Good score by AMD, hopefully they give her the resources she needs to make a difference. I wouldn't hold my breathe though. AMD has this habit of falling on its face.

Prove me wrong AMD. Prove me wrong.