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!

 

[desrever]

Why do people even both watching MLID after the BS of his Zen 4 30% IPC "leaks", expect zen 4 -> zen 4 3D to be less of an upgrade compared to zen 3 -> zen 3 3D because DDR5 is going to already help with some of the memory needs that the cache helps with in the 3D version.

 

[inf64]

It does seem too good to be true, I'd expect something more in line with Zen 3D gains (~15% in games).I expect the vanilla Zen 4 with DDR5 to do much better in games vs vanilla Zen 3 parts and even Zen 3D, especially combined with the higher IPC, DDR5 and much higher boost clocks.

 

[gdansk]

My sources* are telling me that MLID is a fraudulent clickbaiter and that the 7950X3D isn't 30% faster than the 7950X in games.

* I cannot elaborate on my sources any further but their name is gd*nsk

 

[Timorous]

It does seem too good to be true, I'd expect something more in line with Zen 3D gains (~15% in games).I expect the vanilla Zen 4 with DDR5 to do much better in games vs vanilla Zen 3 parts and even Zen 3D, especially combined with the higher IPC, DDR5 and much higher boost clocks.

I could see closer to 20% if they can do it without dropping clocks vs the non 3D versions but more than that seems like a stretch to me and I don't see them going for more than 1 stack and I expect it will be the same 64MB slice they use now so can't see a capacity increase.

 

[Vope45]

Why do people even both watching MLID after the BS of his Zen 4 30% IPC "leaks", expect zen 4 -> zen 4 3D to be less of an upgrade compared to zen 3 -> zen 3 3D because DDR5 is going to already help with some of the memory needs that the cache helps with in the 3D version.

Because he knows his reputation is on the line. I have a feeling tom is really trying to get all his source infos early. He had legit sources for sure but for amd I can't say.

 

[TESKATLIPOKA]

"Only" 5 days until Zen 4 announcement.
How will I endure It?

edit: I am waiting for mobile Zen 4, so still a long way to go.

 

[Thibsie]

"Only" 5 days until Zen 4 announcement.
How will I endure It?

The proper question is (in 5 days) : now that I managed to endure till launch, how can I endure the delay till reviews and next till availability.

You're not finished yet. You will endure way more lol.

 

[Timmah!]

"Only" 5 days until Zen 4 announcement.
How will I endure It?

You wont!

 

[Thibsie]

You wont!

That's the idea ...

 

[Joe NYC]

It does seem too good to be true, I'd expect something more in line with Zen 3D gains (~15% in games).I expect the vanilla Zen 4 with DDR5 to do much better in games vs vanilla Zen 3 parts and even Zen 3D, especially combined with the higher IPC, DDR5 and much higher boost clocks.

Zen 3 3D was probably had a +20% performance gain -5% clock regression.

+30% performance gain too good to be true? He had a line in his slide that V-Cache now works better. There were some bandwidth leaks showing L3 in general had increase in bandwidth.

 

[Det0x]

Zen 4 3D V-Cache blows the doors off

Screenshots from video for those who dont want to watch it:


In the performance comparison between Zen3 and Zen4 AO this is very important information to get across: (Zen4 AO only 5 to 10% faster than Zen3)

 

[DrMrLordX]

Oof March/April 2023 for Raphael-X? I don't know if I can hold out that long.

 

[Joe NYC]

Oof March/April 2023 for Raphael-X? I don't know if I can hold out that long.

AMD said in their Financial Analyst Day:

"We are proud of what vcache technology is doing for us and we gonna feature this in ryzen 7000 series later this year and in the future generations"

From that:
- who knows what feature means
- AMD said a year ago V-Cache would be introduced on desktop, but then changed things and shifted the introduction to Milan-X. Desktop got it much later.

 

[Sable]

Screenshots from video for those who dont want to watch it:
View attachment 66525View attachment 66527View attachment 66528

In the performance comparison between Zen3 and Zen4 AO this is very important information to get across: (Zen4 AO only 5 to 10% faster than Zen3)
View attachment 66529

"Bench 1" "Bench 2"

Seems legit.

 

[DrMrLordX]

AMD said in their Financial Analyst Day:

"We are proud of what vcache technology is doing for us and we gonna feature this in ryzen 7000 series later this year and in the future generations"

From that:
- who knows what feature means
- AMD said a year ago V-Cache would be introduced on desktop, but then changed things and shifted the introduction to Milan-X. Desktop got it much later.

Right I had assumed from the analyst day that it would be November for Raphael-X. MLID is saying that it'll probably just be a demo. Guess I'll have to wait and see. Sigh.

 

[tamz_msc]

From u/Seanspeed on the topic of this latest MLID video:

 

[Racan]

Looks like ASUS will have a mini-ITX board

New X670E motherboards arrive from ROG, ProArt, and ASUS Prime - Edge Up

Our X670 and X670E motherboards from ProArt and Prime family have arrived — and microATX and Mini-ITX gaming motherboards from ROG, too.

edgeup.asus.com

 

[Asterox]

Screenshots from video for those who dont want to watch it:
View attachment 66525View attachment 66527View attachment 66528

In the performance comparison between Zen3 and Zen4 AO this is very important information to get across: (Zen4 AO only 5 to 10% faster than Zen3)
View attachment 66529

Too much confusion about known facts, and all that for new Youtube clicks.

If we now that Zen 4 has 8-10% higher IPC+we now final specification.

R5 7600X, if the rumors are legit

- 700mhz higher Singlecore CPU boost or 5.3ghz
- 5-5.1ghz all cores boost, or 500-600mhz higher vs R5 5600X
- 8-10% higher IPC

Why the comparison with same TDP, we are not comparing laptops.

 

[inf64]

Too much confusion about known facts, and all that for new Youtube clicks.

If we now that Zen 4 has 8-10% higher IPC+we now final specification.

R5 7600X, if the rumors are legit

- 700mhz higher Singlecore CPU boost or 5.3ghz
- 5-5.1ghz all cores boost, or 500-600mhz higher vs R5 5600X
- 8-10% higher IPC

Why the comparison with same TDP, we are not comparing laptops.

Also, some games can benefit greatly from DDR4->DDR5, example Spiderman. Zen 4 without Vcache should be a faster gaming chip than 5800X3D (except in specific games like Flight Simulator that are very cache sensitive).

 

[Timmah!]

Oof March/April 2023 for Raphael-X? I don't know if I can hold out that long.

It might turn out to be true, but i would not put much trust into this video. Its clearly one of those made, when there is actually nothing new to share, but you gotta still produce some content.

 

[eek2121]

Tbh Geekbench has always felt like a better cellphone/light desktop benchmark than something you'd run on a high-end consumer CPU, much less a server/workstation CPU. Even my old 3900X averages ~80W power consumption running the MT test, with the peak being only 125W (out of 142W possible, which is something even Cinebench easily achieves). The CPU is clearly leaving execution resources on the table.

I will have to rerun it on Raphael-X later once I get one to see how bad it is on AM5.

That is because it uses actual workloads. In my experience, it has been pretty accurate at measuring IPC and/or performance and IIRC Dr. Ian Cutress himself stated it was comparable to SPEC.

Real world workloads don’t scale perfectly or linearly.

Geekbench is a solid benchmark that receives way too much hate. Most of that hate comes from the wide variability of results that are published from a wide range of hardware/software configurations ranging from complete garbage to sunshine perfect.

A random result found on their website can be taken with a grain of salt. A result in a carefully controlled environment on the other hand is invaluable for measuring performance.

 

[naad]

You don't need MLID's nonsense to figure out 3d on zen4 will bring more performance than on zen3, first of all packaging has improved notably as with every packaging technology per gen, Raichu I think also confirmed this a few months ago.
As a consequence of this, AMD will be able to hit a higher fmax on the new parts, three things to note about this:

if the 3dcache is running on CCD voltage like it has so far then the fmax will naturally go up since the CCD will require less voltage for a given frequency due to N5
(unlikely) if the 3dcache gets its own voltage plane the above doesn't matter and AMD can and will run the cache at max frequency when they can.
packaging improvements will likely improve the "1.35V" limit 3dcache had, this is a pure gen1 vs gen2 test since it's still on N6

secondly.. people forget 5800x3d was running at 4.5GHz single core, that's 13% off zen3's max boost, that's a pretty big perf uplift by itself zen4x3d gets close to regular SKU clockspeeds.

Lastly AMD has probably done quite a bit of profiling on 3d cache parts in the wild for consumer workloads, that's few % gain in benchmark friendly titles after different firmware with tuned cache heuristics hits.

20%+ is definitely quite possible, 30% is probably closer to upper range of certain games that ham the memory subsystem (spiderman, tomb raider, farcry)

 

[Joe NYC]

secondly.. people forget 5800x3d was running at 4.5GHz single core, that's 13% off zen3's max boost, that's a pretty big perf uplift by itself zen4x3d gets close to regular SKU clockspeeds.

Lastly AMD has probably done quite a bit of profiling on 3d cache parts in the wild for consumer workloads, that's few % gain in benchmark friendly titles after different firmware with tuned cache heuristics hits.

20%+ is definitely quite possible, 30% is probably closer to upper range of certain games that ham the memory subsystem (spiderman, tomb raider, farcry)

Thanks for the 13% figure. Somehow, I had it wrong, thinking it was only 5% clock speed degradation.

So, for 5800x3d, 15% performance gain = 28% gain from V-Cache - 13% clock speed degradation.

In light of this 30% gain for Zen 4, if there is no clock speed degradation seems within reason.

 

[LightningZ71]

The only real data points we have at present are:
TSMC is pushing customers to use N6. N6 SRAM dies were known to be in development. From the die shots of Genoa that we have seen, the CCDs are roughly the same size as Milan. It stands to reason that the cache die for Zen4 is made on N6. N6 brings a notable power and density improvement. Any power improvement will allow more power to be available to the CPU cores. AMD raised the top "TDP" for AM5 over AM4. The main limiting factors for clock speeds for Zen3 X3d were power draw and thermal dissipation (as a function of power draw causing radiated heat). Zen4 CCDs are produced on N5, which has improved power draw and thermal dissipation over Zen 3 on N7.

It stands to reason that the Zen4 X3D will maintain much higher clocks (maybe not 100% of regular Zen4) than Zen3X3d because there will be more available power budget to play with and there will be less excess heat produced by the Cache die because it is expected to draw less power itself. If it does maintain much higher clocks, and has the advantage of the larger cache sizes, it'll be a nice improvement over the 5800X3d. Will it be 30%? It's not beyond the realm of possibility. Why? Zen4 is expected to have a 10% higher IPC at every speed as compared to Zen3. It should be able to have at least a 20% increase in clock speed over the 5800X3d (4.5Ghz * 1.2 = 5.4Ghz, which isn't far fetched given the above and what we have seen AMD demonstrate already). A 20% increase in clock speed and a 10% increase in IPC should allow for a roughly total 30% increase in performance. Increasing DRAM throughput with DDR5 should also allow for an improvement on its own.

So, I don't find the idea that a 7800X3d could be 30% faster than the 5800X3d in cache sensitive application to be impossible. Its certainly optimistic and likely situational based on application cache sensitivity, but it is definitely possible.

 

[Hitman928]

So, I don't find the idea that a 7800X3d could be 30% faster than the 5800X3d in cache sensitive application to be impossible. Its certainly optimistic and likely situational based on application cache sensitivity, but it is definitely possible.

I don't think anyone would argue that this is not very much in the realm of possibility. The issue is, that's not what he said. He said that a Zen4-3d CPU will perform 30% better than a non-3d Zen4 CPU.