Discussion Speculation: Zen 4 (EPYC 4 "Genoa", Ryzen 7000, etc.)

[Vattila]

Except for the details about the improvements in the microarchitecture, we now know pretty well what to expect with Zen 3.

The leaked presentation by AMD Senior Manager Martin Hilgeman shows that EPYC 3 "Milan" will, as promised and expected, reuse the current platform (SP3), and the system architecture and packaging looks to be the same, with the same 9-die chiplet design and the same maximum core and thread-count (no SMT-4, contrary to rumour). The biggest change revealed so far is the enlargement of the compute complex from 4 cores to 8 cores, all sharing a larger L3 cache ("32+ MB", likely to double to 64 MB, I think).

Hilgeman's slides did also show that EPYC 4 "Genoa" is in the definition phase (or was at the time of the presentation in September, at least), and will come with a new platform (SP5), with new memory support (likely DDR5).

What else do you think we will see with Zen 4? PCI-Express 5 support? Increased core-count? 4-way SMT? New packaging (interposer, 2.5D, 3D)? Integrated memory on package (HBM)?

Vote in the poll and share your thoughts!

 

[Ajay]

Zen 4 was never 2021.

I had read at one point that it was, but perhaps that was just a mistake reading the rather vague 'timelines' that AMD puts out publicly.
In any case, I think @moinmoin is correct and AMD just keeps tightening the screws on leaks.

 

[eek2121]

I did some digging. Thus far I've found no evidence that Strix Point is a thing. Big.LITTLE APUs are, yes, AMD filed a patent months ago and most of us have known about it, but the "Strix Point" code name appears to be not real...as of now.

 

[DrMrLordX]

Zen 4 was never 2021.

Technically, Genoa will go to hyperscalars this year, perhaps sooner than any of us know. Zen 4 desktop? Wellllll it could have been, once upon a time, but AMD has practically no incentive to push for that goal so why bother?

 

[DisEnchantment]

Technically, Genoa will go to hyperscalars this year, perhaps sooner than any of us know. Zen 4 desktop? Wellllll it could have been, once upon a time, but AMD has practically no incentive to push for that goal so why bother?

From the Earnings call, it seems some major customers already have access to Zen4 (or at least engaged )

 

[DrMrLordX]

From the Earnings call, it seems some major customers already have access to Zen4 (or at least engaged )

Not at all surprised.

 

[eek2121]

I mean, if Warhol was actually canceled, we could see Zen 4 land this year. Assuming the CCDs are smaller due to 5nm, AMD actually has a strong incentive to accelerate, as long as the capacity is there. Smaller chips = more chips per wafer which means less of a supply issue, which means AMD prints money for another year.

 

[Mopetar]

Plenty of people are waiting to get ahold of a Zen 3 still. There's not too much impetus for AMD to launch Zen 4 this year, particularly now that Intel has played their hand and won't have anything to beat AMD in the desktop market until at least the end of this year or more likely early next.

 

[DisEnchantment]

I am not sure what they will do if they have no more N7 wafers but only N5. Are they going to wait for N7 to be available or use the N5 wafers which are available for something else. Question is if they are ready to produce somethign on N5.
Laptop refreshes from many OEMs are around Q1 and I am very sure they dont want to miss that boat.

 

[jpiniero]

I am not sure what they will do if they have no more N7 wafers but only N5. Are they going to wait for N7 to be available or use the N5 wafers which are available for something else. Question is if they are ready to produce somethign on N5.
Laptop refreshes from many OEMs are around Q1 and I am very sure they dont want to miss that boat.

Rembrant is using N6 so they aren't really affected by N5 supply.

 

[DisEnchantment]

Rembrant is using N6 so they aren't really affected by N5 supply.

N6 and N7 are produced in the same Fabs 15 and 14 with limited quantities in 12 A/B. N7 supply issues affect N6 too
N5 is on Fab 18, different location. That capacity AMD has booked last year. According to Digitimes

 

[moinmoin]

Plenty of people are waiting to get ahold of a Zen 3 still. There's not too much impetus for AMD to launch Zen 4 this year

That didn't delay Cezanne even though Renoir was as scarce.

I am not sure what they will do if they have no more N7 wafers but only N5.

I think for AMD moving to N5 as fast as possible for its own products should be a priority considering N7 by all accounts is more overbooked and highly requested by AMD's partners Sony and Microsoft for their consoles. For these two reasons if AMD wants to go for more quantity of its own chips the only way out is N5.

 

[Mopetar]

For these two reasons if AMD wants to go for more quantity of its own chips the only way out is N5.

They'd want both because moving entirely to 5nm doesn't really change their overall supply. With chiplets the products and allocation of chiplets becomes far more flexible. Even if they make a ton a Zen 4 chiplets, they don't have to put any of them towards desktop CPUs if there's demand from other segments.

You are right about 7nm demand though. The console sales aren't slowing down and both Sony and Microsoft are going to want more chips. I don't thin AMD would be wise to give up any of their own 7nm production. They need it for GPUs and over half of the Zen 3 stack isn't even released yet.

 

[jpiniero]

half of the Zen 3 stack isn't even released yet.

What Zen 3 products have they not released yet? Other than possibly some desktop XT products they are done.

 

[dr1337]

What Zen 3 products have they not released yet? Other than possibly some desktop XT products they are done.

They have a whole 4 skus on desktop out currently. Matisse had 9 before the xt refresh. But to be fair I don't think they have any real motivation to release anything other than the higher end given matisse fills the gaps. I know supporting rome is important but im surprised AMD isn't trying to drop zen 2 production as fast as possible.

 

[jpiniero]

They have a whole 4 skus on desktop out currently.

6 plus the APUs. There really isn't a point in releasing the 5800 and 5900 non-X to DIY since the only difference is the TDP cut... and Epyc is handling any defects.

 

[yuri69]

Wondering about Warhol being a real 2021 standalone product as presented by that infamous roadmap.

We already got leaked CPUIDs for upcoming 2022-scheduled products such as Genoa, Rembrandt, or Raphael. This indicates some kind of documentation describing those products had been available to the leakers.

There has been no Warhol CPUID leak.

 

[Mopetar]

What Zen 3 products have they not released yet? Other than possibly some desktop XT products they are done.

So far they've only released 5950X, 5900X, 5800X, and 5600X. That's four CPUs out of a product stack that typically has at least twice as many parts. There aren't even any non-X or Ryzen 3-series products out yet! How could you say they're even close to done?

 

[jamescox]

For what it is worth, AMD appears to have Warhol as a stand-in for possible 5nm capacity issues OR delayed DDR5 availability. DDR5 looks to be “on track”. Warhol was said to be a DDR4 product and contrary to popular belief, the new die and the old die would not easily interchangeable.

The cancelation rumors may also be completely wrong.

For what it is worth, Only 2 folks have said that it is canceled thus far, and at least one of them is a clown.l and could have gotten it from the other or vice versa.

Which die are you talking about not being easily interchangeable? If the Zen 4 IO die uses the same interface then I would expect that it could be used with a Zen 3 cpu chiplet. If the IO die uses some form of stacking, whether it is an active silicon interposer or some other form of silicon bridge, then it would not be compatible. The question is whether there is a good reason for such a product to exists.

I doubt that AMD would even think of using a different product generation branding (Ryzen 6000) for just a clock speed bump of Zen 3 unless it is a ridiculously large clock speed bump or has other changes. I don’t think we are going to see anything more for AM4 beyond a clock speed bump, so I would only expect an XT model rather than a true Zen 3+. Many enthusiast are not going to invest in AM4 with Zen 4/AM5 coming soon, so the existence of such a product is probably not that likely. Any updates, beyond maybe an XT model with higher clocks don’t really make sense for AM4. You might get some people extending the life of their AM4 boards. I need an upgrade, but with the very limited availability and near EOL of AM4, I am not going to buy one now. It may be that even the XT model was cancelled since they aren’t having any issues selling everything they are making. They don’t need an XT model to boost ASPs; they never went down.

The idea of using a Zen 4 DDR5 IO die with Zen 3, if compatible, doesn’t seem too bad, but it depends on the time frame for Zen 4 and the DDR5 ramp. If Zen 4 is relatively early then they definitely should not make such a part, even though it is attractive to get AM5 / DDR5 ramping. You don’t want to buy Zen 3 based AM5 part at a premium and then have Zen 4 available a short time later.

I have probably flip-flopped on this a lot, but at this point, I am thinking that there isn’t going to be anything new as far as the chiplet based parts until Zen 4 / AM5. We might see a clock speed bump, since that is ridiculously easy to do, but even that seems unnecessary. I guess there could be some interesting APU parts. I haven’t been paying as much attention to the APUs.

 

[jamescox]

Paul reports on a lot of rumors so he's right a lot only because he reports on the rumors that pan out as much as the ones that don't.

If Zen 4 is well along and AMD suspects that Intel is going to have a good showing with their future products there's little reason to devote time to a stop-gap product.

The other side of this could be that AMD was expecting more from Intel in their most recent release and had prepared Zen 3+ as a potential response to regain supremacy. That no longer seems necessary as AMD's biggest issue is being able to supply demand and Zen 3+ does nothing to help that.

Paul makes a lot of videos with very little actual content. The few I have watched are mostly rehashing the same rumor over and over again. It is hard to tell when he actually has a new piece of information. If you believe the video titles, you would think that he has new, world changing information in every one of them. It presumably gets him lots of views, but I am not going to bother watching them.

 

[jamescox]

If AM5 only supports DDR5, yes that could be a problem if it is slipping and/or more expensive than even anticipated.

As someone pointed out, we don’t even have Ryzen 3 5000 series parts or really any non-X series 5000 parts. There isn’t much point in binning any low end parts since they can sell everything they are making as high end parts or Epyc. Ryzen 5000 will probably stick around for a while filling out the low end while Zen 4 based parts are high end and Epyc only.

There isn’t much of a reason for Ryzen 3 5000 chiplet based parts to exist anyway; just use an APU. I would expect most of the low end niches to be filled with APUs. It is unclear what direction this is going as far as the whole product stack. Using one chiplet across the whole market was a massive advantage. They could produce more parts for a given amount of fab capacity by splitting out the IO and using binning. They are probably selling enough Epyc parts now that they don’t really need the volume of the consumer market to reduce cost. There may never be any Zen4 chiplet based part with 8 cores or less. They might just fill that market with APUs that will come later, after DDR5 comes down in cost.

 

[jpiniero]

So far they've only released 5950X, 5900X, 5800X, and 5600X. That's four CPUs out of a product stack that typically has at least twice as many parts. There aren't even any non-X or Ryzen 3-series products out yet! How could you say they're even close to done?

The 5800 and 5900 were released on January 12th. But they are OEM only. There's no point in any quad core CPU Ryzens since yields are good enough that Epyc can take care of those.

 

[Tuna-Fish]

I doubt that AMD would even think of using a different product generation branding (Ryzen 6000) for just a clock speed bump of Zen 3 unless it is a ridiculously large clock speed bump or has other changes.

The branding is not driven by what AMD wants, it's driven by what the OEMs want. When the next generation of laptops launch, they will have Ryzen 6000 series APUs. What, exactly, those chips are depend on what AMD has available at the time. If that's redacted rebrands with maybe 200MHz clock bump, then they are redacted rebrands with a 200MHz clock bump.

Does this suck? Maybe. But it doesn't really matter, because it has been shown time and time again that the OEMs care more about the branding than AMD does, and that AMD is willing to bend over backwards to accommodate them in this. If the OEMs are unwilling to launch a new generation of products with the chips that have the same name, and that's the difference between getting your products in the new hotness, wouldn't you?

Profanity is not allowed in the tech forums.

AT Mod Usandthem

 

[Ajay]

The branding is not driven by what AMD wants, it's driven by what the OEMs want. When the next generation of laptops launch, they will have Ryzen 6000 series APUs. What, exactly, those chips are depend on what AMD has available at the time. If that's shitty rebrands with maybe 200MHz clock bump, then they are shitty rebrands with a 200MHz clock bump.

Does this suck? Maybe. But it doesn't really matter, because it has been shown time and time again that the OEMs care more about the branding than AMD does, and that AMD is willing to bend over backwards to accommodate them in this. If the OEMs are unwilling to launch a new generation of products with the chips that have the same name, and that's the difference between getting your products in the new hotness, wouldn't you?

 

[mikk]

I mean, if Warhol was actually canceled, we could see Zen 4 land this year. Assuming the CCDs are smaller due to 5nm, AMD actually has a strong incentive to accelerate, as long as the capacity is there. Smaller chips = more chips per wafer which means less of a supply issue, which means AMD prints money for another year.

There is no realistic chance. In October last year Zen4 design wasn't even finished.

 

[eek2121]

Which die are you talking about not being easily interchangeable? If the Zen 4 IO die uses the same interface then I would expect that it could be used with a Zen 3 cpu chiplet. If the IO die uses some form of stacking, whether it is an active silicon interposer or some other form of silicon bridge, then it would not be compatible. The question is whether there is a good reason for such a product to exists.

I doubt that AMD would even think of using a different product generation branding (Ryzen 6000) for just a clock speed bump of Zen 3 unless it is a ridiculously large clock speed bump or has other changes. I don’t think we are going to see anything more for AM4 beyond a clock speed bump, so I would only expect an XT model rather than a true Zen 3+. Many enthusiast are not going to invest in AM4 with Zen 4/AM5 coming soon, so the existence of such a product is probably not that likely. Any updates, beyond maybe an XT model with higher clocks don’t really make sense for AM4. You might get some people extending the life of their AM4 boards. I need an upgrade, but with the very limited availability and near EOL of AM4, I am not going to buy one now. It may be that even the XT model was cancelled since they aren’t having any issues selling everything they are making. They don’t need an XT model to boost ASPs; they never went down.

The idea of using a Zen 4 DDR5 IO die with Zen 3, if compatible, doesn’t seem too bad, but it depends on the time frame for Zen 4 and the DDR5 ramp. If Zen 4 is relatively early then they definitely should not make such a part, even though it is attractive to get AM5 / DDR5 ramping. You don’t want to buy Zen 3 based AM5 part at a premium and then have Zen 4 available a short time later.

I have probably flip-flopped on this a lot, but at this point, I am thinking that there isn’t going to be anything new as far as the chiplet based parts until Zen 4 / AM5. We might see a clock speed bump, since that is ridiculously easy to do, but even that seems unnecessary. I guess there could be some interesting APU parts. I haven’t been paying as much attention to the APUs.

It isn’t the same interface. DDR5 alone will require changes, and if it also has PCIE 5? Yeah, no way. The new IOD will need a lot more bandwidth.