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

Page 294 - 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
802
1,370
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

DrMrLordX

Lifer
Apr 27, 2000
21,720
11,014
136
Whenever shipments of Epyc chips reach a level where supply pass demand I can imagine AMD reintroducing non-Pro Threadripper.

That was my suspicion, though there's basically three (actually four?) tiers of demand here:

Level 1: Hyperscalars. ODM sales
Level 2: General market EPYC. Retail.
Level 3: Threadripper Pro
Level 4: Threadripper

AMD will have to exhaust the first three market tiers before they can realistically consider Threadripper again.

MadRat is right. Apple has a serious advantage in the video editing space.

Sure, when fixed-function hardware is in play. Handbrake tells a different story.

The implication there is that AMD only implemented a single AVX-512 Vector unit in Zen4 instead of the dual units in Cascade Lake and Ice Lake Xeon.

Are we still talking about Cinebench ST scores? Cuz Cinebench R23 barely uses anything over AVX2.
 
  • Like
Reactions: Tlh97 and Kaluan

poke01

Senior member
Mar 8, 2022
923
982
106
That was my suspicion, though there's basically three (actually four?) tiers of demand here:

Level 1: Hyperscalars. ODM sales
Level 2: General market EPYC. Retail.
Level 3: Threadripper Pro
Level 4: Threadripper

AMD will have to exhaust the first three market tiers before they can realistically consider Threadripper again.



Sure, when fixed-function hardware is in play. Handbrake tells a different story.



Are we still talking about Cinebench ST scores? Cuz Cinebench R23 barely uses anything over AVX2.
Handbrake is poorly optimised for ARM and highly favours x86 instructions. Also the Air M2 is fanless leading it to throttle. Can AMD perform the same with fanless zen in a laptop?
 

moinmoin

Diamond Member
Jun 1, 2017
4,985
7,751
136
That was my suspicion, though there's basically three (actually four?) tiers of demand here:

Level 1: Hyperscalars. ODM sales
Level 2: General market EPYC. Retail.
Level 3: Threadripper Pro
Level 4: Threadripper

AMD will have to exhaust the first three market tiers before they can realistically consider Threadripper again.
I'd split the levels as follows:
  • High margin: Epyc, Threadripper Pro -> all served during supply constraint
  • Not high enough margin: Threadripper -> not considered until there's some oversupply

Another layer to consider is quantity ordered:
  • High amount in few orders: Cloud -> served first as those ensure a minimum amount of trade right out of the gate even if volume discount reduces margin somewhat
  • Medium amount in more orders: Enterprise and ODM -> served second, slower to expand into but also longer lasting customer base due to slow general turnaround
  • Low amount in too many orders: Retail -> too little quantity, too much price competition, but great for building initial mindshare
 

jamescox

Senior member
Nov 11, 2009
637
1,103
136
Genoa 866
View attachment 65978

vs

Bergamo 897
View attachment 65979

To reduce space(To put 16 pieces of 8 Core CCDs AMD Halved the L3 and removed AVX512, but left AVX256 )
If real, I would have expected Bergamo to be a bit lower clocked, but it is *only* a 64-core processor. If it can clock really high, then perhaps we will see Bergamo chiplets elsewhere. I was thinking that they would have little to no boost clock, which would make them not as attractive for a lot of uses compared to regular Zen 4.
 
  • Like
Reactions: lightmanek

jamescox

Senior member
Nov 11, 2009
637
1,103
136
Perhaps they are using a denser/Shorter AVX512 like they did with PS5 Zen2(compact AVX256), that saved them a 56% die area space.

This is what I believe Bergamo is going to look compared to Genoa.

Bergamo Full ISA compatible(AVX512 with less throughput), 1MiB L2 and 16MiB per CCD. Bergamo lacks the TSV Rails.

View attachment 65987

View attachment 65989
I haven’t seen this before; been out of the loop for a bit. Where are the photos from? Is Bergamo supposed to be 2 CCX per die with 8 cores per CCX?

edit: Bergamo would need to be two of these per die, right? So a 16-core Bergamo die would actually be quite large if that is just half of the die.
 
Last edited:
  • Like
Reactions: lightmanek

rtxtwt

Senior member
Jul 2, 2018
319
505
136
Last edited:

Timorous

Golden Member
Oct 27, 2008
1,684
2,984
136
I can believe halving the L3 for Bergamo. Maths on that just works really. Die size is around 75-80 and with Zen 3 32MB of L3 took up about half of that area. With N5 offering better logic scaling than cache scaling it stands to reason 32MB of L3 will be around 2/3s of the die area give or take leaving 1/3 for cores. Well if you half that L3 you end up with 1/3 cores and 1/3 cache allowing you to add another 8 core cluster for a 16c CCD and use a very similar amount of die area.
 

DrMrLordX

Lifer
Apr 27, 2000
21,720
11,014
136
CPUZ AVX512

Oh okay. Hmm isn't the CPU-Z benchmark mostly integer though?

Handbrake is poorly optimised for ARM and highly favours x86 instructions.

Apple and it's many fans/developers have had plenty of time to address that issue.

Also the Air M2 is fanless leading it to throttle.

Okay whose fault is that?

Can AMD perform the same with fanless zen in a laptop?

I dunno, is anyone dumb enough to sell a >15W PPT Rembrandt in a fanless unit?
 

poke01

Senior member
Mar 8, 2022
923
982
106
Apple and it's many fans/developers have had plenty of time to address that issue.
Yes and no one did. lol
Okay whose fault is that?
It's not a fault per say. It's just how it is.
I dunno, is anyone dumb enough to sell a >15W PPT Rembrandt in a fanless unit?
Well, AMD should make a 9-15W APU. Intel is going to make a 5-10w meteor lake CPU next year. Fanless is good for certain needs like no dust getting into the laptop.
 
  • Like
Reactions: Lodix

eek2121

Platinum Member
Aug 2, 2005
2,942
4,046
136
While IIRC it was stated by an AMD rep that bergamo was cloud specific (no desktop), it would not surprise me at all if AMD pushes out a desktop version down the road. Note that 3D V-Cache would negate the hit by halving L3. AMD could do a 32c/64t Ryzen chip pretty easily with just two chiplets.
 
  • Like
Reactions: inf64

DrMrLordX

Lifer
Apr 27, 2000
21,720
11,014
136
Not sure if Bergamo will ever see an -X variant, nor is it likely that we'll see some weird mobile or desktop chip based on a hypothetical Bergamo-X.
 

Saylick

Diamond Member
Sep 10, 2012
3,233
6,645
136
Seems like the hard launch is indeed pushed 2 weeks back to late Sept due to BIOS-related issues.
 

inf64

Diamond Member
Mar 11, 2011
3,707
4,052
136
Unknown source. Final silicon is ready for sure.

View attachment 66043

Your post got picked up by VIdeocards :D. They are lurking these forums after all.
 

Timmah!

Golden Member
Jul 24, 2010
1,431
665
136
Your post got picked up by VIdeocards :D. They are lurking these forums after all.

Hope he tells us how does it feel to be famous now :)