Tuesday, December 6th 2016
AMD Cripples Older GCN GPUs of Async-Compute Support?
AMD allegedly disabled asynchronous-compute technology support on older generations of Graphics CoreNext (GCN) architecture, since Radeon Software 16.9.2. With the newer drivers, "Ashes of the Singularity" no longer supports asynchronous-compute, a feature that improves performance in the game, on GPUs based on the first-generation GCN architecture, such as the Radeon R9 280X.
"Ashes of the Singularity" benchmarks run by Beyond3D forum members on GCN 1.0 hardware, comparing older drivers to version 16.9.2 shows that the game supports async-compute on the older drivers, and returns improved performance. AMD, on its part, is pointing users to a patch change-list from the developers of "Ashes..." which reads that the game supports DirectX 12 async-compute only on GCN 1.1 (eg: Radeon R9 290) and above.
Source:
Reddit
"Ashes of the Singularity" benchmarks run by Beyond3D forum members on GCN 1.0 hardware, comparing older drivers to version 16.9.2 shows that the game supports async-compute on the older drivers, and returns improved performance. AMD, on its part, is pointing users to a patch change-list from the developers of "Ashes..." which reads that the game supports DirectX 12 async-compute only on GCN 1.1 (eg: Radeon R9 290) and above.
97 Comments on AMD Cripples Older GCN GPUs of Async-Compute Support?
In all truth, nVidia was worst, by crippling performance on 7xx series, while 9xx series was still their current generation...
Shit maybe AMD accidentally broke it who knows for sure yet ?. Don't know about that, it all depends. Dropping the 290 from support would be a terrible thing to do at this time.
Either way, even if something did happen, GCN 1.0 parts are starting to get to the age that many VLIW parts were getting to when AMD decided to ditch support. It wouldn't surprise me if they actually did remove support to further optimize it for GCN 1.1+ but, even with a claim like that, we still don't know.
Edit: The only reason the title is okay is because, there is a question mark at the end. :p
community.amd.com/message/2765237
community.amd.com/message/2765216
Something other than Ashes of the Singularity probably should be used to confirm this. We're putting a lot of faith in a single application to make a very broad claim if we take this at face value.
Gain from Async Compute is between 7% and 10% on R9 270X, 5% and 7% on R9 280X(Maybe more with the same drivers as R9 270X).
Async Compute implementation in Ashes is very light.
Sure not that much(images.anandtech.com/doci/9124/Async_Perf.jpg) but higher than that.
AMD presentation June 2016, Async Compute retired in GCN 1.0 in April.
What AMD seems to have done here is awfully similar. No one can sue, though, since I think async was not an advertised feature, it was enabled down the road. As for "they improved performance to make up for it", that was when Nvidia has done, too, yet people still burn them to the stake because they don't have "proper async".
Personally, I couldn't care less if AMD dropped async support. Yet I cannot help noticing they drop everything they can, as fast as they can (just try to see which hardware is supported by which driver and with witch kernel under Linux). They're short on resources and this trend has me worried.
I think we should all think you for your tests.
I'm very disappointed to see AMD doing such a bad trick. - If the new driver is not optimizing older GCN 1.0 cards, I can understand. But the functions were already there, and now is disabled by new driver? that's a whole other story.
Nvidia used to do that, I was disappointed and came to AMD. Now this happened, next time buying a new Video card I should think again. Who knows, maybe one day AMD will secretly disable another function in another card, because they think it is "old"?
As for 3rd link, shows that it is working but the user failed to include what card he was using.