General Discussions

[black_zion]

According to TomsHardware via GamersNexus via nVidia, they are already working on and implementing a version of AMD's Smart Access Memory. To quote the article

"... the feature looks akin to the PCIe resizable bar feature, a standard feature of the PCIe spec. Nvidia's statement surely suggests that the company feels likewise. If the GPU supports it, adjusting this setting in the motherboard BIOS essentially allows mapping of the full frame buffer, thus improving performance."

If this is true, then it would also mean that there is nothing preventing AMD and nVidia from expanding this feature to previous cards...

https://www.tomshardware.com/news/nvidia-amd-smart-access-memory-tech-ampere

[black_zion]

The WCCFTech's article is a bit more detailed. If I understand this right, there really is nothing aside from a software update keeping it from working on Turing and previous video cards as well. If so, it's going to force AMD to admit BS and enable it on Navi as well...

"According to the tweet which quotes NVIDIA's official response to SAM, the green team confirmed that resizable BAR is a part of the PCI express specifications and that NVIDIA's existing hardware fully supports this functionality. NVIDIA didn't see the need to enable this technology feature until now as its competitor (AMD) is already adding support on its next-gen Radeon RX 6000 series graphics cards based on the RDNA 2 architecture."

https://wccftech.com/nvidia-confirms-ampere-geforce-rtx-30-gpus-to-get-its-own-smart-access-memory-s...

[pokester]

Exactly an no reason 3xx, 4xx chipset boards also can't support this. Of course they should also support PCIe 4 when used with with Zen2 or 3, just like B550 where the PCIe4 support comes from the cpu NOT THE CHIPSET as with x570s additional support. 

It is disappointing that AMD is now trending toward charging for features that should be value added. They didn't used to do this. I guess it is good to be king, or in Lisa's case Queen. 

They however should realize that the community has some supper smart people out there these days and you can't fool them for long. 

AMD already has great reasons to buy their latest products. They don't need to keep technology from their own users who already supported them. 

[black_zion]

Something to think about though is that AMD hasn't provided even first party benchmarks of how SAM boosts performance, they paired it with "rage mode" so how performance is actually affected is still to be seen.

Also remember the previously very hyped Hardware GPU Scheduling, which I believe is still an nVidia exclusive, which provides no noticeable benefit either, so there is a distinct possibility nVidia had disregarded it as negligible and not worth dev time until AMD decided to boast about it due to potential issues which may arise.

[colesdav]

GamersNexus Video:

https://www.youtube.com/watch?v=B8wwwU6-9gA&feature=emb_logo

[colesdav]

GamersNexus Video:

https://www.youtube.com/watch?v=B8wwwU6-9gA&feature=emb_logo

[ajlueke]

I guess the real question is, how much PCIe bandwidth do you need?  The RTX 3090 for example starts to get close to limiting out on PCIe 3.0.  If you allow more of that bandwidth  to be used for CPU/GPU communication, you can "potentially" throttle the GPU.  With PCIe 4.0, there is no chance of that happening.  But, if the gains from better communication outstrip any lost raw bandwidth for the GPU even on PCIe 3 then yeah, no reason not to do it across the board.

[pokester]

Not sure why this shouldn't be able to be enabled in drivers for all cards that meet the PCIe 3 spec or later. Seems silly to call it card specific. I would like to know why this can't work on any such cards from either camp. 

[black_zion]

I still think it's like Hardware GPU Scheduling that there's not much, if any, real world benefit to be seen, and I think AMD not releasing any benchmarks WITHOUT "rage mode" enabled, and nVidia not already having it enabled despite having it working in the lab also lends credence to it, especially since if they did it would really shame AMD for arbitrarily requiring an X570 motherboard and Ryzen 5000 series processor.

[pokester]

I think you are right and it would vary game to game as to if it really helps in a meaningful way. I just think that if you are going to offer it then offer it on all your cards unless there is a reason the others won't support it. 

[black_zion]

MSI is defying convention, at least a little, and enabling SAM on B550 and A520 motherboards as well.

Thing is, since this requires a BIOS update, support for 300 chipsets seems unlikely, and even 400 chipsets are questionable, but nVidia seems to say they are doing it with just a simple software update...

https://wccftech.com/msi-x570-b550-a520-motherboards-support-amds-smart-access-memory/

[pokester]

Seems that if it is part of the PCIe spec then if you are at spec you would not need more than a change to the GPU driver. 

[black_zion]

And looking at the Techspot review which includes SMA/SAM benchmarks, the performance gain is negligible at 4K, suggesting this is a feature which should have been looked into 5 years ago, not in 2020.


https://techspot.com/review/2144-amd-radeon-6800-xt/

[ajlueke]

Esports gamers will take all the frames they can get.

[pokester]

Watched an interview by pcworld with AMD last night recorded yesterday. The AMD rep said that SAM is not necessarily exclusive to x5xx, 5xxx, and 68xx because it can't work on older cards or boards. He said that is all at this point that they have made it ready for and that they are discussing working on making it work on older products but fell shot of a commitment to that effect. 

Personally I hope they do include x4xx boards as I think plenty of those board owners will upgrade to Zen3 and a new GPU if they have an extra incentive. Without it, it kinda rubs you the wrong way knowing it could be supported but they chose to make you buy a new board. So I hope AMD extends the capability retroactively backwards as anything conforming to PCIe 3 can support it. 

[pokester]

This is that interview with AMD and PC World if anyone wants to watch it. 

https://www.youtube.com/watch?v=uaxnvRUeqkg