Xbox One: DirectX 11.1+ AMD GPU , PS4: DirectX 11.2+ AMD GPU what's the difference?

[Silent_Buddha]

The wording "may also be available" does not equal definitely available. It also makes no mention of Tier 1 versus Tier 2 support. Tier 2 support isn't required in order to support PRTs in DX 11.2.

Which again isn't to say that it doesn't have it, but that the quoted update isn't confirmation that it does.

Nvidia's current generation cards also support DX 11.2. But they definitely do not have Tier 2 support. The same goes for GCN 1.0 cards.

Regards,
SB

 

[Shortbread]

The wording "may also be available" does not equal definitely available. It also makes no mention of Tier 1 versus Tier 2 support. Tier 2 support isn't required in order to support PRTs in DX 11.2.

Which again isn't to say that it doesn't have it, but that the quoted update isn't confirmation that it does.

Nvidia's current generation cards also support DX 11.2. But they definitely do not have Tier 2 support. The same goes for GCN 1.0 cards.

Regards,
SB

Does this help? Sounds like hardware (tier 2), straight from the horses mouth.

http://www.heise.de/newsticker/meld...ndig-zu-Direct3D-11-2-kompatibel-1938071.html

Mah also confirmed that the two GPU versions are compatible with the requirements of Direct3D 11.2 in the living room next Playstation 4 and Xbox One. To the requirements of Direct3D 11.2 were . In comparison with the current desktop of the series GPUs Radeon HD 7000 and 8000 Perform calculations more efficiently .HD (OEM) , the console would provide many more variants Asynchronous Compute Engines will Perform calculations more efficiently.

 

[XpiderMX]

Does this help? Sounds like hardware (tier 2), straight from the horses mouth.

http://www.heise.de/newsticker/meld...ndig-zu-Direct3D-11-2-kompatibel-1938071.html

Not again "that" article...

 

[mosen]

Does this help? Sounds like hardware (tier 2), straight from the horses mouth.

http://www.heise.de/newsticker/meld...ndig-zu-Direct3D-11-2-kompatibel-1938071.html

from your link:

The current graphics chips generations Southern Islands and Sea Islands with GCN graphics architecture are based on current not stand for compatible Direct3D 11.2 feature level . And, although AMD had his fingers in the specifications of the new Direct3D specifcation as AMD engineer Laylah Mah said in an interview with c't.

The problem lies in a feedback routine that Microsoft in the final specification transposed differently than assumed by AMD. But that could be solved, such as Mah stressed by a change in the driver. The hardware itself is fully compatible.

Southern Islands and Sea Islands are not DX11.2 feature level compatible and at the same time their hardware itself is fully compatible ?!

 

[Hecatoncheires]

The article says that AMD engineer Laylah Mah told c't that Southern Island and Sea Island GPUs are not compatible with DX11.2 at the moment, but these GPUs will be compatible with DX11.2 after a driver update.

Never rely on automatic translations.

 

[Jay]

My understanding is.

Southern Island is not a single gcn architecture:
All dx11.2 compatible after driver update.
gcn 1.0 -> tier 1
gcn 1.1 -> tier 2

The differences in gcn versions may not be huge, but they are there.

So yes they are all dx11.2 compatible, but one on a hardware level, the other emulating some functions in the driver etc.

 

[Hecatoncheires]

The article says that both Southern Island and Sea Island are fully compatible with DX11.2 on hardware level.

 

[Jay]

That is true all dx11.2 compatible on hardware level at tier 1, gcn1.1 is tier 2.
That's my understanding anyway.

 

[Dave Baumann]

That was like pulling teeth!

 

[eVolvE]

That was like pulling teeth!

Ok, so that sounds like a confirmation

Southern Island is not a single gcn architecture:
All dx11.2 compatible after driver update.
gcn 1.0 -> tier 1
gcn 1.1 -> tier 2

The differences in gcn versions may not be huge, but they are there.

So yes they are all dx11.2 compatible, but one on a hardware level, the other emulating some functions in the driver etc.

So we can assume that tier2 can handle PRT more effectively than tier1 hardware. But we still do not know for sure what that means for the new consoles, do we?

 

[mosen]

Fifty percent of the puzzle has been solved so far

 

[blakjedi]

Fifty percent of the puzzle has been solved so far

Hopefully the second 50% wont devolve into a fan boy fest.

 

[Scott_Arm]

It'll be interesting to see what the tier levels mean. The documentation is not particularly helpful

http://msdn.microsoft.com/en-us/library/windows/desktop/dn280435(v=vs.85).aspx
http://msdn.microsoft.com/en-us/library/windows/desktop/dn280377(v=vs.85).aspx

We at least now know PS4 and Xbox One are at least Tier 1. The extra compute queues in PS4 hint at it being GCN 1.1, maybe, so that could mean it's tier 2. I'm not sure what else we would know about the GPUs to determine if they're GCN 1.1 or not. There seem to be some suggestions Xbox One GPU is GCN 1.1 because of it being capable of 2 primitives per clock. I guess we'll have to wait and see.

 

[blakjedi]

Not sure if it makes much a difference. Amd is also exposing tiled resources through OpenGL 4.4 so there's no real reason why tier 2 support wouldn't be available for both consoles.

 

[Scott_Arm]

Not sure if it makes much a difference. Amd is also exposing tiled resources through OpenGL 4.4 so there's no real reason why tier 2 support wouldn't be available for both consoles.

Well, Dave basically said above that GCN 1.0 is tier 1 and GCN 1.1 is tier 2. So if one console is GCN 1.0, there will be some difference (unknown) between their support of PRT/Tiled Resources.

 

[3dcgi]

There seem to be some suggestions Xbox One GPU is GCN 1.1 because of it being capable of 2 primitives per clock. I guess we'll have to wait and see.

That's bad logic by "some" as Cayman was 2 primitives/clock and it wasn't even GCN.

 

[Jay]

Few reasons I think XB1 would be gcn 1.1, but I'll give one of them, which may not even be the most compelling to be honest.

Why would MS bother even creating tier 2 at the moment, when only a subset of a range of gpu's, from one manufacture would even support it?
I would think they would want windows 8.1 and XB1 to be equivalent in features, at least at the start.
They want developers to be able to easily port from one to the other.
Considering the brute force of PC's I doubt they would think it would be so important to add it in that space when it wasn't in the XB1.
Far from a technical reason :smile:

Doesn't mean Sony's customisations wouldn't have a bigger impact though.

 

[Xenus]

The only way I see one not being Tier 2 is if Tier 2 came about via one companies optimizations and not via AMD Tech. Especially since both companies have already shown of PRT. So it's most logical to assume both are Tier 2 until something very clearly shows one is not.

 

[Bigus Dickus]

No technical reason for thinking this, but if Dave felt it worth us figuring out there is a hardware level difference between tier 1 and 2, I think it is probable that Durango and Orbis are different in this regard. And since it was Dave who tossed out the nugget, I tend to think that implies it is MS with the tier 2 hardware. Could be completely wrong of course.

As for PS4 being more advanced in some ways so obviously it is the tier 2 hardware, I see no compelling reason for that but of course it could be the case. Sony modified a base architecture by requesting more compute queues and resources. I don't see any reason they couldn't have started with the Pitcairn architecture and expanded compute abilities. Bonaire doesn't really match PS4 compute resources either, so either could have been the starting point.

What that means for performance differences, who knows, but if correct even a minor difference could be compounded by the presence of the high speed esram on die. What other implications such gcn 1.0 vs 1.1 differences might have for performance, I have no idea. Maybe none.

 

[Jay]

As for PS4 being more advanced in some ways so obviously it is the tier 2 hardware, I see no compelling reason for that but of course it could be the case. Sony modified a base architecture by requesting more compute queues and resources. I don't see any reason they couldn't have started with the Pitcairn architecture and expanded compute abilities. Bonaire doesn't really match PS4 compute resources either, so either could have been the starting point.

This is also my view.
Sure it doesn't mean they didn't use Bonaire as a base, but it also doesn't mean they did either.

The fact we don't actually know how much the XB1 gpu is customised is besides the point also.

What would be nice to know, is what difference gcn1.1 actually makes.
No one seems to know, as it's architecture that is already out in the wild wonder if Dave is at liberty to say in regards to just DX11.2 tier 1 and 2, in the PC space? Not about consoles.