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

 

[adroc_thurston]

More than 2 GB GDDR chips is on the roadmap... just not yet.

That's GDDR7.

 

[ToTTenTranz]

Man this is pretty raw optimism.

It is?



I'm just expecting a replacement of the 6500XT 8GB with similar price and better performance.

 

[adroc_thurston]

It is?

yea.

I'm just expecting a replacement of the 6500XT 8GB with similar price and better performance.

Bigger die, N4p.
That's $$$.
I'd say $219 or something.

 

[ToTTenTranz]

That's GDDR7.

IIRC GDDR7 supports non-binary sizes, like LPDDR4 and later.

That opens up a bunch of possibilities for Nvidia Blackwell, but not so much for AMD RDNA4.

 

[adroc_thurston]

IIRC GDDR7 supports non-binary sizes

It just lets you have 24/32/moar Gb ICs, all in the JEDEC doc.

 

[ToTTenTranz]

It just lets you have 24/32/moar Gb ICs, all in the JEDEC doc.

Which is great because now you can do 12GB on a 128bit GPU, 18GB on a 192bit GPU, 24GB on a 256bit GPU, etc. without resorting to uneven memory pools like GTX970 and others.

Which makes it much easier to reach a nice pairing between memory amount and GPU performance. It would have come in handy this last gen, for sure.

 

[adroc_thurston]

Which is great because now you can do 12GB on a 128bit GPU, 18GB on a 192bit GPU, 24GB on a 256bit GPU, etc. without resorting to uneven memory pools like GTX970 and others.

Yea but that's still $$$.
You're not getting that additional DRAM for free lmao.

Which makes it much easier to reach a nice pairing between memory amount and GPU performance. It would have come in handy this last gen, for sure.

MONEY.
We're not quite the DRAM drought yet but DRAM still costs real money.
12 gigs on poverty SKUs will not be free.

 

[Mopetar]

$200 is what it should be at launch. $250 is likely what AMD wants to charge. $220 sounds about like what they'll launch at after the $250 price leaks and everyone complains.

With recent inflation levels, $200 isn't as much as it once was.

 

[jpiniero]

$200 is what it should be at launch. $250 is likely what AMD wants to charge. $220 sounds about like what they'll launch at after the $250 price leaks and everyone complains.

With recent inflation levels, $200 isn't as much as it once was.

I think it's going to be $300, at least.

 

[Abwx]

7600 XT 12GB should've been in place of plain 7600 and so on.

7600XT is a 16GB card.

 

[Mahboi]

Technically name and price can change right before announcement, but AFAIK it will look something like this:

N48:
8700 XT 16GB
8600 XT 12GB

Alright, great

N44:
8500 XT 8GB

Amazing

8700 XTX 16GB

NUOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO

 

[igor_kavinski]

7600XT is a 16GB card.

I'm saying a hypothetical 12GB card, if they hadn't planned an 8GB one.

 

[Abwx]

I'm saying a hypothetical 12GB card, if they hadn't planned an 8GB one.

Given the bus 128b width it s either 8 or 16, for 12GB a 192b bus is required, that would add useless costs for what is a low CU count GPU, indeed 40 CUs instead of 32 would had been more on point, dunno why they bother with such low CU count GPU given that the previous gen lower end was already 32 CUs.

 

[ToTTenTranz]

MONEY.
We're not quite the DRAM drought yet but DRAM still costs real money.
12 gigs on poverty SKUs will not be free.

Of course it won't be free, but then just charge extra for the extra RAM.
How much more does a $500 graphics card with 12GB VRAM need to cost if we're to upgrade to 18GB? $550? $580?

That's barely above the premium for a factory overclocked model from some OEM, yet this time we get an actual longevity upgrade.

 

[Mahboi]

Of course it won't be free, but then just charge extra for the extra RAM.
How much more does a $500 graphics card with 12GB VRAM need to cost if we're to upgrade to 18GB? $550? $580?

That's barely above the premium for a factory overclocked model from some OEM, yet this time we get an actual longevity upgrade.

It's not just RAM, it's bus. It's general scaling up. Bigger bus means bigger everything on small dies.
Any 12Go thing would be a lot more at that price range, several dozen percent above.

And you're overreacting, for a "50 XT" 1080p SKU, 8Go is fine. Anybody buying this wants to pay the least possible anyway. And they'll accept to lower to high or medium textures and play their games in peace.

 

[GodisanAtheist]

AMD is better off naming up and pricing down. It would be kinda stupid if they didn't.

Take the N44 which Adroc said is more like $219.

It would be a terrible price for an x500 card (especially when the last one was so maligned) but it would be an incredible price for an 8600. AMD gets to keep their launch price and say there is a gen on gen $50 price drop.

It would be stupid to do it any other way.

 

[Timorous]

AMD is better off naming up and pricing down. It would be kinda stupid if they didn't.

Take the N44 which Adroc said is more like $219.

It would be a terrible price for an x500 card (especially when the last one was so maligned) but it would be an incredible price for an 8600. AMD gets to keep their launch price and say there is a gen on gen $50 price drop.

It would be stupid to do it any other way.

Nah, who cares about the name really. If the price/perf is there it does not matter too much.

 

[Gideon]

Technically name and price can change right before announcement, but AFAIK it will look something like this:

N48:
8700 XTX 16GB
8700 XT 16GB
8600 XT 12GB
N44:
8500 XT 8GB

NIce! I particularily hope the highlighted part is true. The 7600 series was quite a disappointing and having another generation of the same CU count, bandwidth and memory that the RX 6600 would be really sad.

I was initially afraid the 8xxx series would be handled by N44

 

[Mahboi]

AMD is better off naming up and pricing down. It would be kinda stupid if they didn't.

Take the N44 which Adroc said is more like $219.

It would be a terrible price for an x500 card (especially when the last one was so maligned) but it would be an incredible price for an 8600. AMD gets to keep their launch price and say there is a gen on gen $50 price drop.

It would be stupid to do it any other way.

Couldn't disagree more.
After they spent years since RDNA 2 where the main argument was "we have more RAM than them", putting out yet another 6-class with 8Go would earn them nothing but whistles.

$220 for a 50-XT is fine on launch, and it's still sufficient to be a solid 1080p card in 98% of cases. 50 class should mean "can game almost everything on high", not "can game on ultra", so people who will buy it shouldn't expect that they can run every game with max textures or detail, which is exactly where an 8Go card will falter.
It'll be an excellent card for budget buyers, very much cheaper than anything Nvidia or RDNA 3 put out. And if at $220 or even $240 at launch, it can come down to a super low price ($180?) over time.

8600 XT with 12Go is great because it's likely to undercut anything NV will do with VRAM. No "our GDDR7 model has more speed and more VRAM than their paltry GDDR6" when the 3Go GDDR7 chips come out.
It's also going to be a very comfortable 1440p entry level card.

Rest will cover high end 1440p and low tier 4K at a smaller price. It's great, although I don't have any truck with the stupid XTX moniker coming back. I thought it would be associated with RDNA 3's failure and would just disappear in the corridors of History, but apparently no.

I wonder what's the deal with "8700 xt 16Go" and "8700 XTX 16Go" too, if it's just a clock difference between the two? Is it just to help with some low quality dies? Do they expect to mostly sell XTXes?

 

[Kepler_L2]

Couldn't disagree more.
After they spent years since RDNA 2 where the main argument was "we have more RAM than them", putting out yet another 6-class with 8Go would earn them nothing but whistles.

$220 for a 50-XT is fine on launch, and it's still sufficient to be a solid 1080p card in 98% of cases. 50 class should mean "can game almost everything on high", not "can game on ultra", so people who will buy it shouldn't expect that they can run every game with max textures or detail, which is exactly where an 8Go card will falter.
It'll be an excellent card for budget buyers, very much cheaper than anything Nvidia or RDNA 3 put out. And if at $220 or even $240 at launch, it can come down to a super low price ($180?) over time.

8600 XT with 12Go is great because it's likely to undercut anything NV will do with VRAM. No "our GDDR7 model has more speed and more VRAM than their paltry GDDR6" when the 3Go GDDR7 chips come out.
It's also going to be a very comfortable 1440p entry level card.

Rest will cover high end 1440p and low tier 4K at a smaller price. It's great, although I don't have any truck with the stupid XTX moniker coming back. I thought it would be associated with RDNA 3's failure and would just disappear in the corridors of History, but apparently no.

I wonder what's the deal with "8700 xt 16Go" and "8700 XTX 16Go" too, if it's just a clock difference between the two? Is it just to help with some low quality dies? Do they expect to mostly sell XTXes?

-8 CUs on the XT, plus lower power/clocks.

 

[Aapje]

It's not just RAM, it's bus. It's general scaling up. Bigger bus means bigger everything on small dies.
Any 12Go thing would be a lot more at that price range, several dozen percent above.

The context of that discussion was 3 GB GDDR7 chips, so no, the bus size wouldn't have to increase.

It's great, although I don't have any truck with the stupid XTX moniker coming back.

Nvidia has been widening their lineup with the Ti apparently having become a standard part of the entire line-up since Ampere, so it makes sense for AMD to put up the XTX cards against the Ti cards.

Of course, they have to make sure not to mess it up and offer either more performance or better prices at the equivalent tier.

 

[Timorous]

Yea but that's still $$$.
You're not getting that additional DRAM for free lmao.

MONEY.
We're not quite the DRAM drought yet but DRAM still costs real money.
12 gigs on poverty SKUs will not be free.

Does not need to be free, just needs to be a decent value proposition and I think we are at the point where having more than 8GB of VRAM can command a higher price than the cost of adding more VRAM once you want to charge $250 or more.

 

[branch_suggestion]

-8 CUs on the XT, plus lower power/clocks.

They should call them Navi 64/56.

 

[TESKATLIPOKA]

The 7600 series was quite a disappointing and having another generation of the same CU count, bandwidth and memory that the RX 6600 would be really sad.

I honestly don't care If N44 has 32CU + 128-bit GDDR6, If It provides significant upgrade in performance for a reasonable price.
Certainly not happy with 8GB Vram, but If there will be a 16GB option, then ok.
I am still questioning how they want to feed N44 with the same BW as N33.

 

[Mahboi]

Does not need to be free, just needs to be a decent value proposition and I think we are at the point where having more than 8GB of VRAM can command a higher price than the cost of adding more VRAM once you want to charge $250 or more.

"Decent Value proposition" means a minimum of 50$ more per SKU.
So no, for budget buyers it's not free. It's quite the markup, 25% almost.

AMD sells what people buy, and people here should really stop projecting their insecurities about 8Go already. It's still running 95% of games at 1080p Ultra and 98% at 1080p High. For the rest, lowering quality isn't nearly as much of a problem as $50 extra. That's what the budget market is, sacrifices.

I bought budget all my youth and quite a few years beyond, never cared for sacrificing ultra or high in some games, I cared about the 50€.