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

Page 522 - Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.

Vattila

Senior member
Oct 22, 2004
799
1,351
136
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).

Untitled2.png


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! :)
 
Last edited:
  • Like
Reactions: richardllewis_01

eek2121

Platinum Member
Aug 2, 2005
2,874
3,850
136
They are rare but there are a few 220/240 V power supplies out there.

Yes, a same PSU has better efficency with a 220V main compared to a110V one.

This is due to voltage drop in some primary components being much higher with a lower input voltage since it require 2x the current for a same power, that is, 2000W amount to 9 Amperes at 220V and 18 Amperes at 110V.
Unless things have changed since I worked in the sector, IIRC data centers use 230v.
 

Doug S

Platinum Member
Feb 8, 2020
2,174
3,347
136
Unless things have changed since I worked in the sector, IIRC data centers use 230v.

There is no "standard" datacenter voltage. If they use three phase wye they'll be at 208v, if they use split phase 480v they'll be at 240v, and of course 220v and 230v are also prevalent.
 

eek2121

Platinum Member
Aug 2, 2005
2,874
3,850
136
There is no "standard" datacenter voltage. If they use three phase wye they'll be at 208v, if they use split phase 480v they'll be at 240v, and of course 220v and 230v are also prevalent.
208V was actually the one I was thinking about (I am getting old and it's been over a decade since I worked that side of things). It is standard enough that there are numerous product lines for it. It is said to be more efficient, especially here in the US where we've adopted 110v for most things.
 
Jul 27, 2020
15,025
9,255
106
I'm kinda ambivalent about X3D on lower end CPUs. Good for budget users but part of me thinks that V-cache is being wasted. Then again, maybe it's lower quality V-cache that can't be paired with higher frequency CCDs so maybe that makes sense. But I still want them to release the 5900X3D they baited us with and never launched, even if the clocks are as low as a 5600X3D. They could call it 5900X3D Lite Edition.
 

Joe NYC

Golden Member
Jun 26, 2021
1,864
2,147
106
I'm kinda ambivalent about X3D on lower end CPUs. Good for budget users but part of me thinks that V-cache is being wasted. Then again, maybe it's lower quality V-cache that can't be paired with higher frequency CCDs so maybe that makes sense. But I still want them to release the 5900X3D they baited us with and never launched, even if the clocks are as low as a 5600X3D. They could call it 5900X3D Lite Edition.

Where V-Cache would help AMD the most is in 7600x3d. The only Intel CPUs that make some sense to buy are 13/14600. 7600x3d would outperform them in gaming.

My guess is that we will see them after New Year, after AMD caches in on 7800x3d in this shopping season.
 
Jul 27, 2020
15,025
9,255
106
Where V-Cache would help AMD the most is in 7600x3d. The only Intel CPUs that make some sense to buy are 13/14600. 7600x3d would outperform them in gaming.
That's a good idea. I would argue that AMD should have diverted limited supply of V-cache towards arming AM5 since that's the future. But I guess their marketing geniuses must have told them that there's a lot of AM4 users married to their platform who refuse to let go so there's a much better chance of making money by seducing those users with affordable V-cache CPUs. That would basically let them outlive AM5.

In a way, it could be smart. A user in love with their AM4 system looks at AM5 and figures, ehhh..not worth the cost so AMD dangles a cheap V-cache CPU in front of them costing much much less than a platform upgrade.

But it still makes me wonder if those same V-cache dies could be used instead to make 7900X3D and 7950X3D CPUs with two V-cache dies each. I would let AMD do whatever if they didn't gimp high end dual CCD CPUs with only a single V-cache die. After that, if they still have surplus V-cache dies to throw at budget CPUs, sure, knock yourself out AMD.
 

AnitaPeterson

Diamond Member
Apr 24, 2001
5,932
365
126
I get it.

It's a strategy AMD had followed before, back in the days of AM3(+) and FM1/2 sharing the market. One for the mainstream, the other budget.
They are now using AM4 as their budget offering (plus all the enormous existing install base!) while ironing out the kinks of the AM5 platform.

If I'm right, and AMD follows this path, the Ryzen 8xxx series will be OEM-only at launch, with a bigger retail 9xxx series coming shortly after.
 

biostud

Lifer
Feb 27, 2003
18,134
4,577
136

Joe NYC

Golden Member
Jun 26, 2021
1,864
2,147
106
That's a good idea. I would argue that AMD should have diverted limited supply of V-cache towards arming AM5 since that's the future. But I guess their marketing geniuses must have told them that there's a lot of AM4 users married to their platform who refuse to let go so there's a much better chance of making money by seducing those users with affordable V-cache CPUs. That would basically let them outlive AM5.

I wonder if the supply of V-Cache packaging is still limited. The production is finishing the 2nd year.

There is a theory by @adroc_thurston that the newly released AM4 chips are just those that did not pass to be in Milan-X / 5800x3d / 5600x3d. Not a new production, just selling what were formerly rejects.

In a way, it could be smart. A user in love with their AM4 system looks at AM5 and figures, ehhh..not worth the cost so AMD dangles a cheap V-cache CPU in front of them costing much much less than a platform upgrade.

But it still makes me wonder if those same V-cache dies could be used instead to make 7900X3D and 7950X3D CPUs with two V-cache dies each. I would let AMD do whatever if they didn't gimp high end dual CCD CPUs with only a single V-cache die. After that, if they still have surplus V-cache dies to throw at budget CPUs, sure, knock yourself out AMD.

TSMC can make infinite number of these tiny dies. The limiting factor was the assembly capacity. Since this was a cutting edge product, maybe the automation was limited, the tools were just being set up and calibrated.

There were some rumors that AMD bought up 2 years of capacity from TSMC, but now, TSMC is starting to talk about offering it to other customers. Which would imply enough SoIC capacity.
 
Jul 27, 2020
15,025
9,255
106
but now, TSMC is starting to talk about offering it to other customers. Which would imply enough SoIC capacity.
Any link to that? I don't think Intel is interested since they probably don't want the headache of figuring out how to bond TSMC silicon over their internally fabbed compute dies or don't think TSMC can supply them with the needed volume of V-cache dies. They would also not want to use that out of sheer pride since it's something AMD developed in conjunction with TSMC. So who else would want those V-cache dies? I can only think of nGreedia and Apple.
 

Joe NYC

Golden Member
Jun 26, 2021
1,864
2,147
106
Any link to that? I don't think Intel is interested since they probably don't want the headache of figuring out how to bond TSMC silicon over their internally fabbed compute dies or don't think TSMC can supply them with the needed volume of V-cache dies. They would also not want to use that out of sheer pride since it's something AMD developed in conjunction with TSMC. So who else would want those V-cache dies? I can only think of nGreedia and Apple.
There have been some recent presentations in last 6 months about something that TSMC calls "3DBlox" which includes SoIC. TSMC is working with EDA tool vendors to make it easier to incorporate it into the customer designs.
 
  • Like
Reactions: igor_kavinski

manly

Lifer
Jan 25, 2000
10,763
1,916
126
Where V-Cache would help AMD the most is in 7600x3d. The only Intel CPUs that make some sense to buy are 13/14600. 7600x3d would outperform them in gaming.

My guess is that we will see them after New Year, after AMD caches in on 7800x3d in this shopping season.
I see what you did there.

7800X3D is selling well, so there is less immediate need for a 7600X3D for $260ish when considering total platform cost anyway.

Is the reason for this that a 5700X3D will have a lower failure rate than 5800X3D, and therefore can be sold at the lower price without less of a hit to the margins?
I don't geek out on CPUs and components, but aren't the lower end SKUs just dies that didn't pass all the validation to qualify as a 5800X3D? So they would have been tossed out otherwise? I think 4 separate SKUs is way too many; all they need to do is make the 5600X3D generally available rather than a MC exclusive.

IMHO selling one last upgrade for AM4 owners isn't a bad strategy; many aren't yet ready for a full upgrade so capture the incremental sale now. They'll likely be back in about 3 years when they're ready for a new AM5 build.
 
  • Like
Reactions: MadRat
Jul 27, 2020
15,025
9,255
106
There have been some recent presentations in last 6 months about something that TSMC calls "3DBlox" which includes SoIC. TSMC is working with EDA tool vendors to make it easier to incorporate it into the customer designs.

That could open up interesting possibilities. Like suppose V-cache die stacked on top of compute dies and then GPU chiplet stacked on top of the V-cache die, allowing both the CPU and GPU to use V-cache concurrently, making it a very power efficient design, using minimum physical space. That would make for a really cool APU for handhelds.
 

Mopetar

Diamond Member
Jan 31, 2011
7,790
5,887
136
That sounds like a nightmare to cool. Easier to just have the senate CPU and GPU silicon on the same layer with v-cache on top and positioned so that it's not over any of the hotspots.

If you're building an APU you can rearrange everything to make that possible. It's just a matter of using a structure that's effective for both parts and designed so that the CPU and GPU cores aren't thrashing it back and forth and making a big enough mess that a split cache would be better all around.
 

LightningZ71

Golden Member
Mar 10, 2017
1,627
1,898
136

That could open up interesting possibilities. Like suppose V-cache die stacked on top of compute dies and then GPU chiplet stacked on top of the V-cache die, allowing both the CPU and GPU to use V-cache concurrently, making it a very power efficient design, using minimum physical space. That would make for a really cool APU for handhelds.
There's not really an advantage to the tripple stack because the iGPU tile needs to get to the IMC on the base chip anyway. It would be a difficult setup.

There's no reason that AMD couldn't develop an APU with VCache in mind where the VCache die is divided into two regions, where one region is over the L3 for the CCX and the other is over the IMC or iGPU control region with each region dedicated to its particular function. Say AMD chose to do a half sized Vcache die with 32 MB split into two 16MB regions. That would give a HYPOTHETICAL phoenix 1 package with 32MB L3 for the CPUs and a 16MB infinity cache for the iGPU. If the sacrifice is 5% peak clocks to retain the same package power, you'd still come out far ahead overall. When coupled with modern DDR5, it should easily give 6400m+ performance.

If we take that setup to Strix Point, with it's expanded iGPU and RDNA3.5, it would easily exceed 6500m performance. That would be a very compelling part for all of the 1080p market.
 

AnitaPeterson

Diamond Member
Apr 24, 2001
5,932
365
126

I'd say the chances are pretty good that the 5700X3D will become reality.
The 5600x3D was clearly a successful experiment.
 

Tuna-Fish

Golden Member
Mar 4, 2011
1,317
1,432
136
Where V-Cache would help AMD the most is in 7600x3d. The only Intel CPUs that make some sense to buy are 13/14600. 7600x3d would outperform them in gaming.

My guess is that we will see them after New Year, after AMD caches in on 7800x3d in this shopping season.

Wouldn't a slight price cut to the 7700X have mostly the same effect? IMO 7700X and 7800X3D are too close together in price right now, and the market seems to agree, 7700X sales are like 10% of the 7800X3D sales.
 

Joe NYC

Golden Member
Jun 26, 2021
1,864
2,147
106
Wouldn't a slight price cut to the 7700X have mostly the same effect? IMO 7700X and 7800X3D are too close together in price right now, and the market seems to agree, 7700X sales are like 10% of the 7800X3D sales.

Intel's their x700 parts priced at or above 7800x3d. Which makes it a non-brainer to go with 7800x3d.

As far as x600 parts vs. 7700x that comparison is not always in AMD favor, especially in gaming. 7600x3d would take the last niche where Intel is competitive in gaming.
 

Joe NYC

Golden Member
Jun 26, 2021
1,864
2,147
106
I see what you did there.

7800X3D is selling well, so there is less immediate need for a 7600X3D for $260ish when considering total platform cost anyway.

Exactly. the sales during the holidays are higher, and most of those buyers are opting for 7800x3d. If 7600x3d was available during this holiday season, undoubtedly, some of the buyers would shift their purchase to less expensive 7600x3d.
 

FlameTail

Golden Member
Dec 15, 2021
1,644
835
106