Question Speculation: RDNA3 + CDNA2 Architectures Thread

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uzzi38

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DiogoDX

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Oct 11, 2012
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The 7950 XT is probally the full(ish) N31. The 7900 XT is probally the cut down model.
For the skyjuice article I think that will be something like this:

7900 - cut down - 320 bits - 20GB vram
7900XT - full chip - 384 bits - 24GB vram
7950XT - full chip + 3D cache (1hi) - 384bits - 24GB vram - Top card maybe limited and AIO water only to cool the stacked cache
 
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Saylick

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Sep 10, 2012
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For the skyjuice article I think that will be something like this:

7900 - cut down - 320 bits - 20GB vram
7900XT - full chip - 384 bits - 24GB vram
7950XT - full chip + 3D cache (1hi) - 384bits - 24GB vram - Top card maybe limited and AIO water only to cool the stacked cache
According to what I've read on Twitter, seems like the naming has shifted slightly as follows:
  • 7900XT = cut down N31, likely 40-42 WGP w/ 5 MCDs (320-bit bus)
  • 7950XT = full N31, 48 WGP w/ 6 MCDs (384-bit bus)
  • 7950XT3D (?) = 7950XT + V-cache
 
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TESKATLIPOKA

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The problem with RDNA3 is that there are only 3 different chips, Nvidia will have 4-5.
Excluding V-cache It will most likely look like this.
N31: 7900-7950
N32: 7700-7800
N33: 7500-7600
They actually no longer need XT at the end.
 

TESKATLIPOKA

Platinum Member
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Why is that a problem? AMD's chips are supposed to be smaller than nvidia's and both the N31 and N32 can possibly be equipped with vcache and a flexible number of MCD's, to diversify the lineup.
Because there is nothing weaker than a cutdown N33. Phoenix has only 6WGPs, so there is a big void. They will probably rebrand some RDNA2.
I don't expect big gains by equipping vcache.
Naming is also questionable and too similar to Zen4.
One uncut chip is 7950, the other is 7800, One cutdown chip is 7900 and the other 7700 for example.
At least I hope they won't use XT anymore, because that will be useless.
 

biostud

Lifer
Feb 27, 2003
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Because there is nothing weaker than a cutdown N33. Phoenix has only 6WGPs, so there is a big void. They will probably rebrand some RDNA2.
I don't expect big gains by equipping vcache.
Naming is also questionable and too similar to Zen4.
One uncut chip is 7950, the other is 7800, One cutdown chip is 7900 and the other 7700 for example.
At least I hope they won't use XT anymore, because that will be useless.

Do we know that at some point they won't launch a N34? Until we know pricing for next gen, do we know it will be a problem?
 
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TESKATLIPOKA

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Do we know that at some point they won't launch a N34? Until we know pricing for next gen, do we know it will be a problem?
If they later released a N34 with 10WGP for lowend that would be great. A possible problem would be Vram size, unless they go for 128bit. 64bit -> 4GB; 96bit->6GB; 128bit->8GB.

Do you think a RX 7500 will be priced lower than $399?
My guess for prices, It could be even higher.
RX 7500(N33) -> $399
RX 7600(N33) -> $499
RX 7700(N32) -> $699
RX 7800(N32) -> $799
RX 7900(N31) -> $999
RX 7950(N31) -> $1099
RX 7990 + 3dcache(N31) -> $1299
These prices are already way better than what Nvidia set for their cards so far.
RTX 4080 12GB(AD104) -> $899
RTX 4080 16GB(AD103) -> $1199
RTX 4090 24GB(AD102) -> $1599
 
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biostud

Lifer
Feb 27, 2003
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If they later released a N34 with 10WGP for lowend that would be great. A possible problem would be Vram size, unless they go for 128bit. 64bit -> 4GB; 96bit->6GB; 128bit->8GB.

Do you think a RX 7500 will be priced lower than $399?
My guess for prices, It could be even higher.
RX 7500(N33) -> $399
RX 7600(N33) -> $499
RX 7700(N32) -> $699
RX 7800(N32) -> $799
RX 7900(N31) -> $999
RX 7950(N31) -> $1099
RX 7990 + 3dcache(N31) -> $1299
These prices are already way better than what Nvidia set for their cards so far.
RTX 4080 12GB(AD104) -> $899
RTX 4080 16GB(AD103) -> $1199
RTX 4090 24GB(AD102) -> $1599

It will be interesting to see if the N31/N32 segregation will happen with different numbers of MCD as well as active WGP's

Alternatively:

RX 7500(N33) 6GB-> $329
RX 7600(N33) 8GB -> $399
RX 7700(N32) 12GB -> $599
RX 7800(N32) 16GB -> $699
RX 7900(N31) 20GB -> $899
RX 7950(N31) 24GB-> $1099
 
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Timorous

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Oct 27, 2008
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It will be interesting to see if the N31/N32 segregation will happen with different numbers of MCD as well as active WGP's

Alternatively:

RX 7500(N33) 6GB-> $329
RX 7600(N33) 8GB -> $399
RX 7700(N32) 12GB -> $599
RX 7800(N32) 16GB -> $699
RX 7900(N31) 20GB -> $899
RX 7950(N31) 24GB-> $1099

That is the stack I see. Pricing seems low for the top end because looking at the 4090 results I can see the 7950 being 10-20% faster if the TBP is 420W and the perf/watt increase is 50%.
 

Mopetar

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Jan 31, 2011
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They'll segment based on bus size. NVidia already does it with their monolithic dies and AMD would probably like to be able to use chiplets with defects preventing them from connecting to the full number of MCDs.
 

Saylick

Diamond Member
Sep 10, 2012
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If they later released a N34 with 10WGP for lowend that would be great. A possible problem would be Vram size, unless they go for 128bit. 64bit -> 4GB; 96bit->6GB; 128bit->8GB.

Do you think a RX 7500 will be priced lower than $399?
My guess for prices, It could be even higher.
RX 7500(N33) -> $399
RX 7600(N33) -> $499
RX 7700(N32) -> $699
RX 7800(N32) -> $799
RX 7900(N31) -> $999
RX 7950(N31) -> $1099
RX 7990 + 3dcache(N31) -> $1299
These prices are already way better than what Nvidia set for their cards so far.
RTX 4080 12GB(AD104) -> $899
RTX 4080 16GB(AD103) -> $1199
RTX 4090 24GB(AD102) -> $1599
It will be interesting to see if the N31/N32 segregation will happen with different numbers of MCD as well as active WGP's

Alternatively:

RX 7500(N33) 6GB-> $329
RX 7600(N33) 8GB -> $399
RX 7700(N32) 12GB -> $599
RX 7800(N32) 16GB -> $699
RX 7900(N31) 20GB -> $899
RX 7950(N31) 24GB-> $1099
Prices seem a little low... I still feel like full N31 will be $1200+ and the V-Cache variant likely another $200 on top of that. I'd love to be wrong though. $1099 for N31 that ties a 4090 in raster would be super sweet.
 

TESKATLIPOKA

Platinum Member
May 1, 2020
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It will be interesting to see if the N31/N32 segregation will happen with different numbers of MCD as well as active WGP's

Alternatively:

RX 7500(N33) 6GB-> $329
RX 7600(N33) 8GB -> $399
RX 7700(N32) 12GB -> $599
RX 7800(N32) 16GB -> $699
RX 7900(N31) 20GB -> $899
RX 7950(N31) 24GB-> $1099
Very cheap. Not like I would mind that, but I don't think AMD will play Santa.
I expect 128bit 8GB for RX 7500, last time they used 6GB was with RX 5600, but that one had 192bit GDDR6.
 

biostud

Lifer
Feb 27, 2003
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Very cheap. Not like I would mind that, but I don't think AMD will play Santa.
I expect 128bit 8GB for RX 7500, last time they used 6GB was with RX 5600, but that one had 192bit GDDR6.
Here's to hoping.

Obviously AMD wants profit, but they also wants market shares and sell in volume. So I guess it depends on the balance of costs, performance and profit/unit compared to nvidias products.

Personally I hope for something that push prices. But I guess we all do. :p
 

Timorous

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Oct 27, 2008
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Here's to hoping.

Obviously AMD wants profit, but they also wants market shares and sell in volume. So I guess it depends on the balance of costs, performance and profit/unit compared to nvidias products.

Personally I hope for something that push prices. But I guess we all do. :p

N33 is smaller and on a cheaper node than N23. A $400 7600XT will have far higher margins than the 6600XT and if it performs in the 6800-6800XT tier at 1080p/1440p then it will be a great card.
 

Saylick

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Sep 10, 2012
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Also, on the eve of what might be a leak with clockspeeds and performance targets, does anyone want to make their final guesses? This pump that dumps fuel into the hype train's engine ain't going to prime itself! :p

Here, I'll start. My guess for full N31 specs:
- Up to 60% perf/W uplift over N21
- 1.8x - 2x raster uplift
- 2.2x to 2.5x RT uplift
- 3.1 GHz game clock
- 375W TDP
- 24 GB GDDR6 RAM
 

maddie

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Jul 18, 2010
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Also, on the eve of what might be a leak with clockspeeds and performance targets, does anyone want to make their final guesses? This pump that dumps fuel into the hype train's engine ain't going to prime itself! :p

Here, I'll start. My guess for full N31 specs:
- Up to 60% perf/W uplift over N21
- 1.8x - 2x raster uplift
- 2.2x to 2.5x RT uplift
- 3.1 GHz game clock
- 375W TDP
- 24 GB GDDR6 RAM
I see >375W & >2X raster. AMD seems no longer reluctant to pushing power limits.
 
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Timorous

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Oct 27, 2008
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I expect a 420W TBP and with a 50% perf/watt gain that is 2.1x the 6900XT so about 10-20% faster than a 4090 at 4K.

Same sums were used when estimating N21 performance from 5700XT and that was bang on the money for the 4K advantage the 6900XT had over the 5700XT and I don't think AMD will change how they have done their perf/watt for the last few gens.
 

exquisitechar

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Apr 18, 2017
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I said before that AMD probably won’t beat the 4090ti in raster or RT, and it still seems that way now. Given the chiplet design, it seems that they were conservative with Navi31 and they could have built a significantly faster GPU. It competing with AD102 at all is an achievement, and it puts them in a good position, cost-wise. As for RT performance, I would be disappointed if they can’t beat the 4080 16GB. Aside from the massive increase in compute contributing to that, I hope they made specific RT related improvements.