Discussion RDNA4 + CDNA3 Architectures Thread

[DisEnchantment]

With the GFX940 patches in full swing since first week of March, it is looking like MI300 is not far in the distant future!
Usually AMD takes around 3Qs to get the support in LLVM and amdgpu. Lately, since RDNA2 the window they push to add support for new devices is much reduced to prevent leaks.
But looking at the flurry of code in LLVM, it is a lot of commits. Maybe because US Govt is starting to prepare the SW environment for El Capitan (Maybe to avoid slow bring up situation like Frontier for example)

See here for the GFX940 specific commits

History for llvm/lib/Target/AMDGPU - llvm/llvm-project

The LLVM Project is a collection of modular and reusable compiler and toolchain technologies. - History for llvm/lib/Target/AMDGPU - llvm/llvm-project

github.com

Or Phoronix

More AMD "GFX940" Enablement Work Landing In LLVM - Phoronix

www.phoronix.com

There is a lot more if you know whom to follow in LLVM review chains (before getting merged to github), but I am not going to link AMD employees.

I am starting to think MI300 will launch around the same time like Hopper probably only a couple of months later!
Although I believe Hopper had problems not having a host CPU capable of doing PCIe 5 in the very near future therefore it might have gotten pushed back a bit until SPR and Genoa arrives later in 2022.
If PVC slips again I believe MI300 could launch before it

This is nuts, MI100/200/300 cadence is impressive.



Previous thread on CDNA2 and RDNA3 here

Question - Speculation: RDNA3 + CDNA2 Architectures Thread

Man I have been dying to make this one for a while now. First rumours for RDNA3 are here so new thread time! Just going to start off with this one for now: kopite7kimi on Twitter: "@VideoCardz Ah, I mean a simple mcm design with 10240 cores is not enough. Because the lift from RDNA2 to RDNA3...

forums.anandtech.com

 

[soresu]

Extrapolate your own opinion as to why. Is it discounts or seasonal consumerism? Who cares, it's the time.

Opinion isn't necessary to extrapolate that it is impossibly stupid to only make significant discounts a mere 2 months before your planned launch if you still have inventory overflowing with last gen product.

They have been trying to shift it for quite a while and it's pretty clear at this point that they overestimated demand when they made the order.

RDNA3 was overdue because of COVID.

RDNA4 is now overdue because they couldn't shift already produced RDNA3 SKUs due to lack of interest or falling market spending.

(overdue relative to AMD's own past statements that new product generations be less than 18 months apart)

 

[gdansk]

Opinion isn't necessary to extrapolate that it is impossibly stupid to only make significant discounts a mere 2 months before your planned launch if you still have inventory overflowing with last gen product.

They have been trying to shift it for quite a while and it's pretty clear at this point that they overestimated demand when they made the order.

RDNA3 was overdue because of COVID.

RDNA4 is now overdue because they couldn't shift already produced RDNA3 SKUs due to lack of interest or falling market spending.

(overdue relative to AMD's own past statements that new product generations be less than 18 months apart)

Mucho texto.
They have discounts now too.
But there is no point launching the new product *before* the big inventory moving month (which is, has been, and will be November).

Anyone telling you RDNA4 is arriving before December is listening to charlatans. Even board partners have suggested next year. For obvious reasons (they suffer the most).

If you are disappointed they didn't announce anything at Gamescom or TGS then you're listening to clowns.

 

[inquiss]

Que?

Sell out inventory in the road up to Christmas and during black Friday, I think is the point being made.

 

[soresu]

Sell out inventory in the road up to Christmas and during black Friday, I think is the point being made.

I got that, I just don't think it's very likely at this point unless they cut really deep and just live with their losses come CES.

 

[branch_suggestion]

AMD’s Radeon 890M: Strix Point’s Bigger iGPU

AMD’s iGPUs have seen plenty of recent success. Handheld gaming devices like Valve’s Steam Deck and Asus’s ROG Ally both use AMD integrated graphics. AMD’s last generation m…

chipsandcheese.com

 

[marees]

56 CU 16 gb version

https://twitter.com/x/status/1827937117328007293

 

[lucasworais]

56 CU 16 gb version

https://twitter.com/x/status/1827937117328007293

2.1GHz?

 

[marees]

2.1GHz?

That is just testing limit

In reality around 3 Ghz

Ideally RDNA 4 Ghz

 

[DisEnchantment]

56 CU 16 gb version

https://twitter.com/x/status/1827937117328007293

They all disappeared from GB database. 56CU sounds like a harvested 64CU part.

 

[Tuna-Fish]

That is just testing limit

In reality around 3 Ghz

Ideally RDNA 4 Ghz

I wouldn't be willing to quote any actual speed, but yes, it's common for ES chips of all varieties to be clocked arbitrarily low.

They all disappeared from GB database. 56CU sounds like a harvested 64CU part.

Really hoping that they do this and don't gimp the memory interface for the harvested part. 18Gbps GDDR6 is getting really cheap.

 

[igor_kavinski]

18Gbps GDDR6 is getting really cheap.

Could they do a 512 bit part with that memory? Something with 32GB VRAM?

 

[marees]

Mostly I was not buying 2025 from all the drivers being apparently ready and it makes no sense to release for CES.

Look at the November-early Dec spike. That's Christmas effect on buys, and it works every year since the 70s at least. Even if we are in a hard recession (and we are), there's no point holding out for AFTER that. Not unless you're seriously late. Even botched RDNA 3 came out early Dec.

Dang, that would've been a really impressive ticking for a GPU.
I'm holding out for a personal copium of 3.3GHz. Because it sounds nice and fast.

Who in their right mind would expect that? The amount of light bounces is still designed by and for Nvidia, it won't be doing any good in say Cyberpunk. But if it gets out of being poor man's RT and becomes "RT but less good", its already great. Frankly, that "8700 XTX" or whatever it's called will be a gaming monster. 4K is still mostly a waste of money for 3D gaming (I say this sitting in front of my 4K monos) and 1440p is still the prime cost/perf target. If they're going for a cost/perf gen, there's no better target than a top tier 2K card, and this is it. 4070 Ti RT? 7900 xt and above raster? Yep, that's perfect, buy buy buy.

Release date was always a business decision

The geekbench leak proves that hardware is ready
Past data reveals a nov-dec spike

What will AMD decide 🤔

(Powercolor rep stating no RDNA 4 this year &
The leaked 56 CU & 2.1 Ghz being very close to a simulated PS5 pro GPU makes me very nervous)

 

[Kepler_L2]

The geekbench leak proves that hardware is ready

This leak might be A0, which is not the final revision.

 

[branch_suggestion]

https://twitter.com/x/status/1828223002586050648

Big if true, but more importantly the naming.
Assuming AMD uses XTX for the top SKU of a generation, then I'd like the naming to be:

N48
8700XTX
8700XT
8600XT
N44
8500XT
8500

Clearly segmenting by VRAM, nice and clean.

 

[marees]

https://twitter.com/x/status/1828223002586050648

Big if true, but more importantly the naming.
Assuming AMD uses XTX for the top SKU of a generation, then I'd like the naming to be:

N48
8700XTX
8700XT
8600XT
N44
8500XT
8500

Clearly segmenting by VRAM, nice and clean.

There is no sign of a 8500 at this stage. As of now navi 44 seems to have a single (high yield) version

Another point to keep in mind is that a potential cut down navi 44 will have to compete vs 6nm n33 (7600 & 7600xt). Those are potentially long running cards & in no danger of being stopped anytime soon

 

[marees]

There is no sign of a 8500 at this stage. As of now navi 44 seems to have a single (high yield) version

Another point to keep in mind is that a potential cut down navi 44 will have to compete vs 6nm n33 (7600 & 7600xt). Those are potentially long running cards & in no danger of being stopped anytime soon

Shipping manifests also have so far revealed only 4 in total across n44 & n48

https://twitter.com/x/status/1828316425209164079

 

[branch_suggestion]

There is no sign of a 8500 at this stage. As of now navi 44 seems to have a single (high yield) version

Which makes sense, any N44 cutdown would be OEM only as yields should be extremely high.

 

[ToTTenTranz]

https://twitter.com/x/status/1828223002586050648

Big if true, but more importantly the naming.
Assuming AMD uses XTX for the top SKU of a generation, then I'd like the naming to be:

N48
8700XTX
8700XT
8600XT
N44
8500XT
8500

Clearly segmenting by VRAM, nice and clean.

So the rumors about Navi 48 topping at 18Gbps were incorrect.

I guess it's good news if AMD thinks the SoC runs fast enough to justify the higher clocked memory.

 

[SolidQ]

So the rumors about Navi 48 topping at 18Gbps were incorrect.

Interesting MLID talking half year ago
14.30+

 

[ToTTenTranz]

Could they do a 512 bit part with that memory? Something with 32GB VRAM?

I read somewhere that it was hard/expensive to do 512bit on GDDR6 because it requires too many layers and long routes on the PCB, and at that point they're better off going with HBM.

 

[marees]

Interesting MLID talking half year ago
14.30+

18gbs bottlenecked the 7900 gre
It will definitely bottleneck the navi 48 top card that is supposed to perform between 7900 gre & 7900 xt

So top navi 48 (64 CU) should launch for $600 with high speed 20gbs ram

There could be a cheaper version (54 CU) next year for $480+

I don't see navi 44 launching in Q1 next year. Should be Q2 next year. No idea what memory speed AMD might use. It should perform like a 4060 ti 8gb & cost between $300 to $330

I don't see the need for a 12gb 48 CU navi 48 as long as 7700xt & 7800xt remain on the market

If the top n48 launches this year (for $600 approaching 4070 ti super level of performance) that could disrupt prices of 7900xt, 4070 ti super & 4070 super . But I am skeptical AMD will launch this year, if they have tons of unsold RDNA 3. At the bare minimum RDNA 2 (6800 & 6750xt) have to sell out so that AMD can then start discounting the price of 7800xt & 7700xt if top N48 launches this year

 

[ToTTenTranz]

Interesting MLID talking half year ago
14.30+

Interesting. That video is from 6 months ago but what he says about Samsung's 24Gbps memory is still true. It's been on "sampling" for over 2 years now, meaning they haven't really found a way to make GDDR6 work at those speeds.


Though I wonder if we'll eventually see some factory overclocked 3rd party Navi 48 graphics cards using those 24Gbps chips. It's still a 20% difference in VRAM bandwidth which is probably noticeable enough for higher resolutions.

 

[SolidQ]

supposed to perform between 7900 gre & 7900 xt

Isn't from Kepler it was between XT and XTX?

 

[marees]

Isn't from Kepler it was between XT and XTX?

That seems optimistic. I expect raster to be between 7900gre & 7900xt based on available information

 

[SolidQ]

That seems optimistic. I expect raster to be between 7900gre & 7900xt based on available information

New wgp + high clock, should be between XT and XTX
Mlid also always stays between XT and XTX, in worst scenario like XT