Discussion RDNA 5 / UDNA (CDNA Next) speculation

[marees]

If UDNA is unified RDNA5 and CDNA4, then given that MI400 is officially said to be out in H1 2026, then surely consumer RDNA5 should also be out by end of that year at least?

Did you mix up CDNA 4 & CDNA 5 ?

(going forward AMD claims CDNA will be revised every year unlike RDNA which is revised once in 2 years)

 

[Win2012R2]

Did you mix up CDNA 4 & CDNA 5 ?

Well, AMD said the next one will be unified and at the time CDNA3 was already out in form of MI300, therefore it should be CDNA4 which is MI400 = early next year.

 

[reaperrr3]

gfx9 to gfx10 lmao

As far as I remember, GFX10 "only" upgraded the CUs and introduced ShaderArrays as sub-units of SEs, but still carried over a bunch of legacy "baggage" from Vega with little changes.

If UDNA is unified RDNA5 and CDNA4, then given that MI400 is officially said to be out in H1 2026, then surely consumer RDNA5 should also be out by end of that year at least?

From what kepler et al said before, UDNA is just marketing fluff for the fact that their development pipelines and architectures aren't completely separate anymore and will now take more of a tandem/leapfrog approach, so any improvements made to CDNA can also be leveraged in the next RDNA if useful and vice-versa, but they're still distinct enough that the release of next CDNA doesn't necessarily say much about the release of the next RDNA.

 

[Win2012R2]

so any improvements made to CDNA can also be leveraged in the next RDNA if useful and vice-versa

That's not unified.

Unified is what Nvidia has got - same CUDA code works on 3050 and B200

Looks like it is indeed marketing fluff (AKA blatant lies).

 

[soresu]

so any improvements made to CDNA can also be leveraged in the next RDNA if useful and vice-versa

I think at the CU level besides gfx specific silicon CDNA will be just a generation behind RDNA going forward.

This should mean in theory that standing up ROCm/HIP support for RDNA5+ in ROCm is going to be of much higher priority by default.

As doing so will be a necessary step to standing up the next gen of CDNA from which their greater revenue fraction stems.

This also means that any new µArch features less than well rounded can be dogfooded in RDNA prior to implementation in CDNA, and likewise for software in ROCm.

 

[marees]

Well, AMD said the next one will be unified and at the time CDNA3 was already out in form of MI300, therefore it should be CDNA4 which is MI400 = early next year.

My understanding is that

MI350 is CDNA 4
MI400 is CDNA 5
MI500 is CDNA 6?

& so on

 

[marees]

My understanding is that

MI350 is CDNA 4
MI400 is CDNA 5
MI500 is CDNA 6?

& so on

Well, AMD said the next one will be unified and at the time CDNA3 was already out in form of MI300, therefore it should be CDNA4 which is MI400 = early next year.

From AMD's own website: CDNA 4 is already released this year

CDNA Next is next year

https://www.amd.com/en/technologies/cdna.html

 

[marees]

From AMD's own website: CDNA 4 is already released this year

CDNA Next is next year

https://www.amd.com/en/technologies/cdna.html

I believe CDNA 5 is not official yet

AMD Instinct MI350 288GB GPU Offering 35x AI Inference Performance Next Year

AMD Instinct MI325X with 288GB of HBM3E memory is for 2024, while the MI350X with CDNA 4 offers 35x AI Inference performance in 2025

www.servethehome.com

 

[Win2012R2]

My understanding is that

MI350 is CDNA 4

If it was CDNA4 then why didn't they call it MI400?

My understanding that they've decided to run extra teams to improve MI300 whilst MI400 is still worked on - possibly pulling some things like 4/6 bit stuff that was badly needed, borrowing off CDNA4 does not making it CDNA4.

MIx00 convention is also clearly indicating CDNAx level.

 

[marees]

If it was CDNA4 then why didn't they call it MI400?

My understanding that they've decided to run extra teams to improve MI300 whilst MI400 is still worked on - possibly pulling some things like 4/6 bit stuff that was badly needed, borrowing off CDNA4 does not making it CDNA4.

MIx00 convention is also clearly indicating CDNAx level.

I gave you link to official AMD pages where MI350x is CDNA 4

You can wish that MI & CDNA numbering should track each other but that is not reality

BTW cdna 4, 5, & 6 in one image below

https://www.crn.com/news/ai/2025/the-biggest-amd-advancing-ai-news-from-mi500-gpu-to-rocm-enterprise-ai?page=4

 

[Win2012R2]

I gave you link to official AMD pages where MI350x is CDNA 4

Where does it say CDNA4 next to MI350?

 

[marees]

Where does it say CDNA4 next to MI350?

This one below

(This is where this thread title comes from)

I believe CDNA 5 is not official yet

View attachment 128857

AMD Instinct MI350 288GB GPU Offering 35x AI Inference Performance Next Year

AMD Instinct MI325X with 288GB of HBM3E memory is for 2024, while the MI350X with CDNA 4 offers 35x AI Inference performance in 2025

www.servethehome.com

 

[Win2012R2]

This one below

ok, you got me confused with the last image was trying to find CDNA4 there!

Indeed, it appears that MI350 is CDNA4, at least in marketing speak it is officially.

 

[soresu]

ok, you got me confused with the last image was trying to find CDNA4 there!

Indeed, it appears that MI350 is CDNA4, at least in marketing speak it is officially.

Yes, or GFX950 in internal parlance.

 

[adroc_thurston]

GFX10 "only" upgraded the CUs

Yeah the most relevant part.

and introduced ShaderArrays as sub-units of SEs

They existed for god knows how long for i$/k$ sharing.
gfx10 wholly changed the internal organization of the GPU.

but still carried over a bunch of legacy "baggage" from Vega with little changes.

Wtaf does that mean

 

[marees]

So if xbox next is ready to be revealed by Nov next year then surely AT2 must be fully baked by then ?

& by corollary the entire RDNA 5 architecture should be frozen by then 🤔

Next Call Of Duty — Modern Warfare IV, due to be released in June next year — is apparently being tested on next xbox dev kit, & will not be released for PS4, or XBone generations

https://twitter.com/x/status/1896672391457349981

So likely 2026 end launch in time for xbox's 25th anniversary

you may already have seen the claim that Microsoft's next-gen Xbox could land next year.​

​

Originally expected to launch in 2027 or 2028, the console could now potentially be released in 2026 due to a claim made by Call of Duty insider TheGhostofHope.​

​

They took to social media to announce several details about 2026’s franchise release which is assumed to be Modern Warfare IV.​

​

It’s the added detail though that MWIV will supposedly have “no old gen support” and is being “developed on dev kits for the next Xbox” that’s got people talking.​

Xbox next-gen console release date leak leaves fans furious

Microsoft's next-gen Xbox is due to land next year, but many fans feel that's too soon.

www.gamingbible.com

 

[soresu]

So if xbox next is ready to be revealed by Nov next year then surely AT2 must be fully baked by then ?

& by corollary the entire RDNA 5 architecture should be frozen by then 🤔

Nah you don't need 1:1 hardware for a dev kit, it just has to support roughly the right feature set.

 

[marees]

MLID hallucinations cum leaks

Forget the RX 9900 XTX: AMD's RDNA 5 Based 10900 XT May Feature 36 GB VRAM & ~10K Cores [RUMOR] | Hardware Times

AMD’s Radeon RX 9000 GPUs perform rather well in recent titles, outmaneuvering pricier GeForce counterparts in Hellblade 2 and Battlefield 6. Unfortunately for Radeon fans, RDNA 4 is absent from the enthusiast segment, leaving the RTX 4090 and 5090 without competition. RDNA 5 (UDNA) is expected...

hardwaretimes.com

 

[marees]

Cc @dangerman1337

AT3 — 48 CU 384 bit lpddr6
AT4 — 24 CU 128 bit lpddr6

 

[adroc_thurston]

AT4 — 24 CU 128 bit lpddr6

wow if Medusa premium survived that would be kinda interesting

 

[marees]

wow if Medusa premium survived that would be kinda interesting

There are now 2

Mega & Mini

Medusa not so halo = AT4 (24 CU 128bit) — shares socket with strix halo ?
Medusa halo = AT3 (48 CU 384bit)

 

[adroc_thurston]

Mega & Mini

It's called Medusa Premium and Medusa Halo.

 

[marees]

Cc @dangerman1337

AT3 — 48 CU 384 bit lpddr6
AT4 — 24 CU 128 bit lpddr6

Any guesses on (2027) launch prices ??

1. AT0 (10090xt > 5090) — 384 bit bus so $1500+ ?
2. AT1 (10080xt) — scrapped
3. AT2 (10070xt = 5080 > xbox next) — 72 CU 192bit gddr7 so $600+
4. AT3 (10060xt < 5070) — 48 CU 384bit lpddr6 so $400+
5. 9060xt 16gb (=ps5 pro) ~ $300
6. AT4 (10050xt > 3060 12gb in raster) — 24 CU 128bit lpddr6 so $250 ?

 

[Joe NYC]

It's called Medusa Premium and Medusa Halo.

Funny how I said in the past that AMD should turn GPU into a chiplet, you said it would never happen, and here we are.

That was a vision of extreme modularity and reuse, and now AMD is doing it.

The Medusa Halo seems to have:
1. base monolithic CPU / SoC chiplet
2. standalone 12 full core CPU chiplet
3. standalone big GPU chiplet

Medusa Mini (Premium)
1. base monolithic CPU / SoC chiplet
2. standalone small GPU chiplet

2 versions of standalone GPUs from those chiplets

consoles made from same (similar) components

Very elegant

 

[adroc_thurston]

The Medusa Halo seems to have:
1. base monolithic CPU / SoC chiplet
2. standalone 12 full core CPU chiplet
3. standalone big GPU chiplet

oh no that's not how any of that works.

Medusa Mini (Premium)
1. base monolithic CPU / SoC chiplet
2. standalone small GPU chiplet

no, GPU is the SOC tile.