5-Way Mesa 12.1-dev + Linux 4.7 Git Radeon Comparison

[bridgman]

Wait... was it confirmed that both freesync and crossfire are definitely coming to the proprietary stack (and going to be implemented before they are in the free software stack)? Has an ETA been posted?

Nothing has been confirmed, but we are working on freesync.

AMD has been marketing two RX 480 cards in Crossfire beating a GTX1080 at a cheaper price point, which would be amazing... only I was under the impression we were never going to see that on GNU/Linux, under either driver stack. I'd buy two RX 480 cards at launch if I knew they were going to work well enough in Crossfire, even if it was only for the proprietary drivers at first (as long as there was a promise that it would come to the free software stack too within the next six months), but sadly I don't recall seeing anyone at AMD make any such claim.

For clarity, we are absolutely *not* doing any marketing based on Crossfire. The demo used at the launch used application-level multi-GPU support via DX12... the equivalent for Linux would be app-level multi-GPU via Vulkan, not Crossfire.

[theriddick]

According to Brigman Crossfire(driver based Alternate Frame Rendering (AFR)) is dead because modern graphic effects need multiple frames in order to form a modern graphic effect

Not sure what affects your talking about. For DX9-DX11 AFR did work, were just some problems due to lack of support in some games. Clearly it's not needed for DX12 and Vulkan as they have some special code to do mGPU inbuilt. Shame no crossfire for OpenGL however, damn shame.

I'll use whatever driver is better, atm that is the PRO driver. When the day comes that open one is better, I'll use that. But atm its missing allot of stuff and only works on half of the games I have...

[theriddick]

Perhaps, either way it seems crossfire is dead. Gonna be a lot of unhappy people who buy 2x480 and struggle getting it working.

[bridgman]

According to Brigman Crossfire(driver based Alternate Frame Rendering (AFR)) is dead because modern graphic effects need multiple frames in order to form a modern graphic effect this means it is incompatible to AFR. This means only explicit multi gpu support via vulkan have any future.

...

According to Bridgman freesync is coming for the opensource driver. (3-4 months)

Q, can you please stick to quoting me and not claiming I said something different ?

I didn't say Crossfire/SLI was dead, but I did say it was becoming increasingly difficult to support in drivers and apps as a result of a long list of issues where access to previous frames was just one example... and that the games which were sufficiently advanced to need the extra performance of multi-GPU hardware were also generally the most difficult to support. Given the availability of new APIs that explicitly expose multiple GPUs to the game engine I see that style of multi-GPU support becoming dominant quite quickly.

re: freesync I said that it is being worked on. Nothing more.

[bridgman]

I think your complex excuses "increasingly difficult to support" resulting in no support at all on linux and openGL...

It's more than that... Windows and DX as well AFAICS.

[fuzz]

but but but,,, it is really just a complex and long version of: it is death...

but OK I understand that you can not say this because you work for this company.

On the other hand we are not in the Windows XP days any more (of 12 years old stuff) no one in the linux world will stay on old-code for long. and Opensource projects like games or game engines will adopt vulkan very fast.

Do you have a poster of bridgman on your wall or something?

[bridgman]

but but but,,, it is really just a complex and long version of: it is death...

I do agree that driver-only multi-gpu will die eventually (and probably fairly soon)... I'm just trying to make the distinction between "dying" and "already dead".

[bridgman]

Yep, fair point - but since the same game code runs across multiple platforms I don't think we can draw hard lines between Linux & Windows hjere.

If you think "Linux-only" then you're probably not going to get any multi-GPU games anyways. You generally get games that work with multi-GPU when substantially the same code is used across Linux and Windows, ie where the Windows market can subsidize the Linux support. As OpenGL became used less in Windows games that cross-subsidization started to disappear (and Crossfire/SLI compatibility with it), but with Vulkan (and even with DX12 on Win / Vulkan on Linux to some extent) it has a chance of coming back again via explicit multi-GPU support.