Discussion RDNA 5 + CDNA 4 Architectures Thread

Kronos1996

Member
Dec 28, 2022
64
106
76
Now seems like a good time to start this discussion thread. Per AMD’s earnings call yesterday, CDNA 4 is coming out mid-2025. MI350 sounds like it uses the new architecture with the same packaging/platform while MI400 is a top to bottom redesign.

RDNA 5 seems to be 18 months away minimum (late 2026 launch per leaked roadmaps.) Still, they should have the architecture locked in. Might get some info on the dies later this year when they start tape-out’s.

My main question is if these two architectures are the first step in the UDNA merge? Same base architecture heavily customized for gaming and server. Essentially what Nvidia’s been doing for years.

Not that dissimilar to AMD’s approach with Zen either. Classic core, Dense Core and modular add-ons like X3D. They can add/remove IP like AVX-512 depending on the market. Most importantly, all the variants are software compatible.

It sounds like they want to take a similar approach with UDNA. Unified software stack for a unified base architecture. My guess is, a new modular CU. Then they can insert whatever IP is appropriate for each product line. Rasterization + RT hardware for gaming. The whole shopping list of AI instructions for datacenter. Optimized density for each depending on the clock-speed targets.

David Wang made remarks about how changing the cache system resets software optimization to zero. Is it safe to assume both products lines will share a similar memory system design?
 
  • Like
Reactions: moinmoin and Tlh97

marees

Golden Member
Apr 28, 2024
1,015
1,360
96
There is a one / one-and-a-half year gap between CDNA 4 & RDNA 5

So maybe the one after CDNA 4 could be the UDNA version ??
 

Kronos1996

Member
Dec 28, 2022
64
106
76
There is a one / one-and-a-half year gap between CDNA 4 & RDNA 5

So maybe the one after CDNA 4 could be the UDNA version ??
Could be yeah. I thought MI350 was a relatively new addition and they originally planned CDNA 4 to debut with MI400? If that’s the case, then CDNA 4’s launch has been moved up considerably.
 

GTracing

Senior member
Aug 6, 2021
478
1,111
106
My main question is if these two architectures are the first step in the UDNA merge?
There is a one / one-and-a-half year gap between CDNA 4 & RDNA 5

So maybe the one after CDNA 4 could be the UDNA version ??
Jack Huynh hinted that the RDNA5/CDNA4 generation won't be fully unified when he announced the UDNA name. It sounds like it will called UDNA regardless of whether RDNA and CDNA are merged into one architecture or not.
PA: So, this merging back together, how long will that take? How many more product generations before we see that?

JH: We haven’t disclosed that yet. It’s a strategy. Strategy is very important to me. I think it’s the right strategy. We’ve got to make sure we’re doing the right thing.
 
  • Like
Reactions: Tlh97 and Elfear

basix

Member
Oct 4, 2024
106
221
76
MI400 should already be CDNA5. So maybe RDNA6 & CDNA5 = UDNA? Huynh mentioned framed it as a cloud-to-client strategy, which wold match that. CDNA5 is first and RDNA6 follows. RDNA5 could be still somewhat close to RDNA2 which might be better for next-gen consoles also.
 

CakeMonster

Golden Member
Nov 22, 2012
1,604
782
136
If this is the basis for hardware in the next gen consoles I really hope they can cram as much 'universal' hardware units as possible in there so that it will run future stuff we can come up with as AI models are trained in 1-2-5 years, similar to transformer based upscaling now running on 2018 Turing hardware.
 
  • Like
Reactions: Tlh97 and marees

rommelrommel

Diamond Member
Dec 7, 2002
4,423
3,206
146
If this is the basis for hardware in the next gen consoles I really hope they can cram as much 'universal' hardware units as possible in there so that it will run future stuff we can come up with as AI models are trained in 1-2-5 years, similar to transformer based upscaling now running on 2018 Turing hardware.

The transformer model runs on Turing, but so poorly you won't use it.
 
  • Like
Reactions: Thunder 57

soresu

Diamond Member
Dec 19, 2014
3,712
3,037
136
CDNA 4 will deliver the biggest generational leap in AI performance in our history, with a 35 times increase in AI compute performance compared to CDNA 3.
Lisa Su in the CDNA4 product development meetings.....

moar_chiplets.jpg
 
  • Haha
Reactions: Tlh97