Discussion Zen 5 Speculation (EPYC Turin and Strix Point/Granite Ridge - Ryzen 9000)

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BorisTheBlade82

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May 1, 2020
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Yikes, looks like the rumor of Zen 5 + Zen 4D could be true after all
View attachment 78615
View attachment 78612
Reading Family ID is not sufficient anymore, now there are core level differences and the CPU Topology has to be read as well.
Amazing, were did you find that?
Slowly but surely all my wild speculations come true.
Next stop: IFoP successor 😎
 

Timmah!

Golden Member
Jul 24, 2010
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Same thought, I only want the Zen 5 cores, not some puny outdated Zen 4c inebench cores. :)


I would guess one 8C Zen 5 Chiplet + 16C Zen 4 Chiplet for 24C.
So going by PHX2 topology, Zen 4c would have half the L3 per Core but for 16C in one CCX the amount of L3 would still be same? That could make L3 available to a core to the SW pretty much same even though L3 per core is half. But overall around same size as Zen 4 CCD but 2x cores, if going with PHX density of 25 MTr@178mm2
View attachment 78613

Meh. Give me 24 Zen5 cores not these hybrids. If i wanted that, i could get Intel CPU.

BTW, only now read about Turin etc...was not paying attention to these future Epycs and whatnot before, last thing i knew was Zen4 Genoa 96C and Zen4C Bergamo 128C. So is Turin Zen5 = Genoa replacement and supposedly up to 192 cores, did i understand that right? And if yes, they are still keeping 8 cores per chiplet? Cause that would be 24 chiplets on one CPU...is it going to have 24 RAM channels? Or would 2 chiplets share single channel? Somehow i find this hard to believe to be truth...then again, what do i know.
 

Joe NYC

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Jun 26, 2021
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Meh. Give me 24 Zen5 cores not these hybrids. If i wanted that, i could get Intel CPU.

BTW, only now read about Turin etc...was not paying attention to these future Epycs and whatnot before, last thing i knew was Zen4 Genoa 96C and Zen4C Bergamo 128C. So is Turin Zen5 = Genoa replacement and supposedly up to 192 cores, did i understand that right? And if yes, they are still keeping 8 cores per chiplet? Cause that would be 24 chiplets on one CPU...is it going to have 24 RAM channels? Or would 2 chiplets share single channel? Somehow i find this hard to believe to be truth...then again, what do i know.

I think Turin will have 16 x 8 Core CCDs = 128
The Bergamo successor will likely have 12 x 16 core CCDs = 192

The socket stays the same, so the same 12 channels of memory.
 

Timmah!

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Jul 24, 2010
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I think Turin will have 16 x 8 Core CCDs = 128
The Bergamo successor will likely have 12 x 16 core CCDs = 192

The socket stays the same, so the same 12 channels of memory.

I see, that makes more sense. I read something about 192/256, so i thought 192 for Turin and 256 for Bergamo replacement.
 

Geddagod

Golden Member
Dec 28, 2021
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Same thought, I only want the Zen 5 cores, not some puny outdated Zen 4c inebench cores. :)


I would guess one 8C Zen 5 Chiplet + 16C Zen 4 Chiplet for 24C.
So going by PHX2 topology, Zen 4c would have half the L3 per Core but for 16C in one CCX the amount of L3 would still be same? That could make L3 available to a core to the SW pretty much same even though L3 per core is half. But overall around same size as Zen 4 CCD but 2x cores, if going with PHX density of 25 MTr@178mm2
View attachment 78613
Zen 4C CCD is 50% bigger than the Zen 4 chiplet?
If Zen 5 uses that, I don't expect prices to be pretty for consumers
Especially since I think, at best, the Zen 5 chiplet is going to be the same size as the Zen 4 standard chiplet.
But also, wasn't there talk of Zen 4C using an even smaller cell type than Zen 4? Seeing how Zen 4 already uses HD libs, idk if AMD would go for even denser libs (or even if TSMC offers them as standard or if AMD would have to make their own libs), so idk how true this is.
Also, why use a Zen 4C chiplet anyway? Do we even know if Zen 4C will offer better MT perf/mm^2 or perf/cost than Zen 5? Over Zen 4 it's obvious, but for Zen 5 idk, since the node is similar so costs would be similar there, and Zen 5 should offer significant IPC gains... maybe if someone can do some rough napkin math for how much better Zen 5 would have to be to get better perf/watt over Zen4C...
If they do end up using Zen 4C though, hopefully we get a Zen 5 with V-cache and Zen 4C chiplet as an option...
 

turtile

Senior member
Aug 19, 2014
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Zen 5 is definitely not coming in 2023. AMD stated that it is a 2024 product. And since AMD refreshes their mobile line up every March, and has stated that the next mobile chip is based on Zen 5, we can conclude that Zen 5 should be out in March or April 2024.

The only thing I can see happening is AMD moving Zen 4 to a custom N4X for a November release. Zen 4 is smaller and the improved process can probably hit 6.2 Ghz. This extra clock speed would allow AMD to better compete with Intel in the mid to low-end retail space while Zen 5 takes the high end.
 

DisEnchantment

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Mar 3, 2017
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Amazing, were did you find that?
Slowly but surely all my wild speculations come true.
Next stop: IFoP successor 😎
From the manual for Phoenix and the generic architecture reference document.
The only thing I can see happening is AMD moving Zen 4 to a custom N4X for a November release. Zen 4 is smaller and the improved process can probably hit 6.2 Ghz. This extra clock speed would allow AMD to better compete with Intel in the mid to low-end retail space while Zen 5 takes the high end.
N4P should be enough for Zen 4 to reach 6.2 GHz. N4X is leaky and density is not great, from commercial perspective it will be not suitable for Zen 4.

Zen 4C CCD is 50% bigger than the Zen 4 chiplet?
If Zen 5 uses that, I don't expect prices to be pretty for consumers
PHX has a density of 140MTr/mm2. And the Zen 4 cores there hit 5.2 GHz. 16C Zen 4c with half L3 fabbed like this will be similar to a standard 8C Zen 4 chiplet in size, ~66 mm2.

Especially since I think, at best, the Zen 5 chiplet is going to be the same size as the Zen 4 standard chiplet.
That can't be the case.
From commercial perspective,
Zen 2 --> Zen 3 CCD got a 12% bump in area at a time when N7 is just in its 3rd year of production and AMD is unable to meet console SoCs demand and N7 supply is highly contested.
Zen 4 --> Zen 5 CCD should be >10% bump in area, when N5 family is in its 5th year of production (yes it is old) and additional AZ F21 fab online and in 2024 N5 wafer output will be close to double that of N7 in 2020 and other TSMC customers moving to N3 and AMD using N3, N5, N7 nodes at that point instead of just one.
From another perspective, Zen 4 CCD is very tiny, at 66.3 mm2 far below the optimal TSMC sweet spot of 80 mm2. Zen 3 is 80.7 mm2 partly because of this metric. N5 could actually improve this metric. It is 5 years old in 2024 after all.

Also, why use a Zen 4C chiplet anyway? Do we even know if Zen 4C will offer better MT perf/mm^2 or perf/cost than Zen 5? Over Zen 4 it's obvious, but for Zen 5 idk, since the node is similar so costs would be similar there, and Zen 5 should offer significant IPC gains... maybe if someone can do some rough napkin math for how much better Zen 5 would have to be to get better perf/watt over Zen4C...
If they do end up using Zen 4C though, hopefully we get a Zen 5 with V-cache and Zen 4C chiplet as an option...
Actually good point why Zen 4c, why not Zen 5c. But AMD differentiate efficiency cores from performance cores based on process efficiency mainly so they might not be ready to fab Zen 5c on N3E yet.
 
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BorisTheBlade82

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Zen4c will pretty surely have a better perf/mm2 than even Zen5. Almost doubling this KPI from OG Zen4 should sail them through this.

I would guess that the c-core line will be lagging the OG cores timeline-wise. For me it looks like this:
  1. Zen4 in every segment
  2. Zen4c in Bergamo and MI300
  3. Zen4c in PHX2
  4. Zen4c with Zen5 in the Desktop
  5. Zen4c with Zen5 in mobile
  6. Zen5c in DC
  7. ...
 

cortexa99

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Jul 2, 2018
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Meh. Give me 24 Zen5 cores not these hybrids. If i wanted that, i could get Intel CPU.

BTW, only now read about Turin etc...was not paying attention to these future Epycs and whatnot before, last thing i knew was Zen4 Genoa 96C and Zen4C Bergamo 128C. So is Turin Zen5 = Genoa replacement and supposedly up to 192 cores, did i understand that right? And if yes, they are still keeping 8 cores per chiplet? Cause that would be 24 chiplets on one CPU...is it going to have 24 RAM channels? Or would 2 chiplets share single channel? Somehow i find this hard to believe to be truth...then again, what do i know.

It looks like AMD just only use Zen4C in its monolithic die like APUs which need to save place for mobile usage. When comes to dual CCD designs like Raphael it's close to impossible since the IO is limited to 8 core per CCD, and significantly contradict X3D dual CCDs design because AMD need high clock/X3D cores at the same time, while high density cores provide nothing.

My thought is AMD has many option but they don't need to, practically.

 
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naukkis

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Jun 5, 2002
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When comes to dual CCD designs like Raphael it's close to impossible since the IO is limited to 8 core per CCD,

IO isn't limited to number of cores. Cores even don't access IO-die at all, they access L3 and when L3 misses it will make a request to IO-die. CCD of course can have more than one L3 like it was case with original Ryzen, there was two L3-domains that make request to integrated IO-part. If Zen4c-chiplet have shared L3 for all its cores it can be used with two chip configuration with Raphael IO too - other hand if it have two CCXs and two L3 clusters only one of such chip can be paired with Raphael IO-die which can only serve two L3-domains.
 
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BorisTheBlade82

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It is about certain that one Zen4c Bergamo CCD is housing 2 CCX with 8 cores each. These two CCX do not share their L3, just as was the case with Zen2.

Regarding the interconnect to the IOD the picture is much more blurry:
  • One option is: The current EPYC IOD has 12 IFoP links. So the up to 8 Bergamo CCD could get connected via one link each. That could get them bandwidth starved as this is only half the bandwidth per core as Desktop and Server Zen4 have.
  • Another option: From my measurements it seems, that MI300 employs 24 Zen4c cores, not Zen4. One die could be the plain old 16c die for Bergamo. And that might be connected via Infinity Fan-out Links AKA InFO-RDL. This would bring them plenty bandwidth even with a rather narrow link. So for me it is quite possible, that starting with Bergamo and later on with Desktop Zen5 AMD will get rid of the current IFoP.
 

Kepler_L2

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It is about certain that one Zen4c Bergamo CCD is housing 2 CCX with 8 cores each. These two CCX do not share their L3, just as was the case with Zen2.

Regarding the interconnect to the IOD the picture is much more blurry:
  • One option is: The current EPYC IOD has 12 IFoP links. So the up to 8 Bergamo CCD could get connected via one link each. That could get them bandwidth starved as this is only half the bandwidth per core as Desktop and Server Zen4 have.
  • Another option: From my measurements it seems, that MI300 employs 24 Zen4c cores, not Zen4. One die could be the plain old 16c die for Bergamo. And that might be connected via Infinity Fan-out Links AKA InFO-RDL. This would bring them plenty bandwidth even with a rather narrow link. So for me it is quite possible, that starting with Bergamo and later on with Desktop Zen5 AMD will get rid of the current IFoP.
The CCDs in MI300 are on top of the base I/O die and connected via SoIC.
 
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BorisTheBlade82

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The CCDs in MI300 are on top of the base I/O die and connected via SoIC.
Right, they are connected to a base die via SoIC. But how are the four base dies connected to HBM and quite likely each other as well? The most likely answer after having a look at N31 is InFO-RDL. Another option would be EFB for connecting the base dies to each other.
 

BorisTheBlade82

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cortexa99

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Gigabyte's spokesman must be trembling right now.

 

Doug S

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Well, for the MCD in N31 we already have 1 TByte/s. This can be increased quite easily by using more beachfront.
Apple's M1 Ultra, which employs InFO-LSI or EFB also has only 2.5 Tbyte/s.


Apple is using a massive number of I/Os clocked fairly slowly to minimize power consumption. It is the result of a different set of goals.
 

Doug S

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So you are saying, they may have decreased TSMC's pj/bit figures by lowering the GByte/mm as well through lower clocks?

Yes, similar to how you can reduce watts per unit of performance by undervolting & underclocking a CPU. We know Apple is using on the order of 10,000 I/Os and the data rate is 2.5 TB/sec i.e. ~2 Gbps per pin. So it should be easy to calculate the specifics and compare if TSMC has released the required detail.
 

A///

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Feb 24, 2017
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Zen 5 is definitely not coming in 2023. AMD stated that it is a 2024 product. And since AMD refreshes their mobile line up every March, and has stated that the next mobile chip is based on Zen 5, we can conclude that Zen 5 should be out in March or April 2024.

The only thing I can see happening is AMD moving Zen 4 to a custom N4X for a November release. Zen 4 is smaller and the improved process can probably hit 6.2 Ghz. This extra clock speed would allow AMD to better compete with Intel in the mid to low-end retail space while Zen 5 takes the high end.
as i suspected it's another xt. sit back and wait for @DrMrLordX to complain about the xts again.
 

Kocicak

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Jan 17, 2019
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I dont understand what should I complain about...

Seeing the post by Turtile
This extra clock speed would allow AMD to better compete with Intel in the mid to low-end retail space while Zen 5 takes the high end.
I can just remark that thanks to Intel flooding the CPUs with E cores it is very hard to compete with them in the low/mid end market segment.
 

A///

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Feb 24, 2017
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I dont understand what should I complain about...
Nothing, he doesn't want to admit he's fussy about AMD's release schedule. the pandemic messed up their scheduling. IIRC Zen 4 was later than expected at 24 months. Zen 5 returns to the 14-18 month schedule they had prior.
 

Tigerick

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Apr 1, 2022
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There is new leaks from RGT about Strix Point, AMD seems like going to split the APU design into 3 die, below is comparison table:

NameModelLaunch DateNodeCPU coresL3 CacheMemory LPDDR5xMemory BWGPUALUICTDP
PHX2R5
7040
Q3 2023N4 115mm22xZen4 + 4xZen4c4+4=8MB64-bit 750060 GB/sRDNA3 4CU 256SP256NA15W
STX3R5
8050
Q3 2024N4P2xZen5 + 4xZen5c12 MB64-bit 853368 GB/sRDNA3+ 4CU 256SP512NA15W
PHX+R7&9
8040
Q1 2024N4P8xZen416 MB128-bit 8533136 GB/sRDNA3+ 12CU 768SP1536NA15-45W
STX2R7
8050
Q3 2024N4P4xZen5 + 8xZen5c24 MB128-bit 8533136 GB/sRDNA3+ 8CU 512SP1024NA15-45W
STX1
Halo
R9 8050Q3 2024N4P + N4P8xZen5 + 8xZen5c32 MB256-bit 8533272 GB/sRDNA3+ 20CU 1280SP256032MB25-120W
6xZen5 + 8xZen5c28 MB128-bit 8533136 GB/sRDNA3+ 10CU 640SP128032MB
Fire RangeR7&9
8055
Q3 2024N4P x 316xZen564 MB128-bitRDNA3+ 2CU 128SP256NA55W+

Guess AMD still going monolithic with Strix Point with 3 different dies :rolleyes:
 
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Joe NYC

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There is new leaks from RGT about Strix Point, AMD seems like going to split the APU design into 3 die, below is comparison table:

PHX2N4 115mm22xZen4 + 4xZen4c8MBRDNA3 4CU 256SP15W
STX3N4P2xZen5 + 4xZen4c8MBRDNA3+ 4CU 256SP15W
STX2N4P4xZen5 + 8xZen4c16MBRDNA3+ 8CU 512SP~30W?
STX1N3E8xZen5 + 8xZen4c32MBRDNA3+ 16CU 1024SP~35W?

Guess AMD still going monolithic with Strix Point with 3 different dies :rolleyes:

Kind of boring, I have to say.

The STX1 would seem quite big to be a monolithic die.

It would be surprising if AMD ends up with ~250+ mm2 monolithic die to go against chiplet based Meteor Lake and Arrow Lake. I don't see this as likely...