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

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Vattila

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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).

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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! :)
 
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Exist50

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They say 14% in one of their press releases.
These new Ryzen 7000X3D are the fastest gaming processors in the world.4 With up to 14% faster performance than the previous generation.6 The AMD Ryzen 7000 Series processors with 3D V-Cache technology will be available for Socket AM5 starting February 2023.
Footnotes seem broken, however, so can't tell what they're comparing.
 

BorisTheBlade82

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I think it's even more complicated. Frequency vs cache sensitivity and scheduling decisions would require some really deep telemetry. Nothing like that on the market today, as far as I'm aware.
Totally agree with you here. It's going to be a nightmare. If I understand the statement in the THG article correctly, we will get Gaming chipset drivers that will be updated frequently in order to explicitly specify which strategy to apply for which Game.
The problem I have with this approach is that quite likely only AAA titles will be explicitly optimized and at some point in the future they will simply stop integrating new games.
 
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tamz_msc

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Please, stop embarrassing yourself by bringing up the production capacity.
He was talking about performance and efficiency, and you know It.

Intel has a serious problem with U and P series.
7940HS is 34% faster in CB R23 than i7-1280P and Raptor will be barely faster, because It's the same chip only a bit higher clocked.

I know, we don't have the actual TDP for them only official 35-45W vs 28W and that U series would make a better comparison.
Still, at comparable TDP an 8C16T Phoenix should be faster than 6P8E20T i7-1370P.
The only problem Intel has with efficiency is the high idle power draw caused by the PCH consuming too much power in the Alder Lake-P CPUs. That should be fixed with Raptor Lake-P. Everybody knows that AMD's specs for TDP are meaningless when it comes to laptops, as these CPUs have a short duration power limit over and above TDP that lasts for much longer than tau on Intel CPUs, so no comparison at similar power levels is possible, especially between HS and P SKUs.
 
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Exist50

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Totally agree with you here. It's going to be a nightmare. If I understand the statement in the THG article correctly, we will get Gaming chipset drivers that will be updated frequently in order to explicitly specify which strategy to apply for which Game.
The problem I have with this approach is that quite likely only AAA titles will be explicitly optimized and at some point in the future they will simply stop integrating new games.
Yeah, I have to figure they'd use a whitelist of sorts. Maybe they could have some heuristics, but how else would they even know that a given app is a game? Would be interesting for someone to try out exe renaming and see if it has an effect.

Though if these optimizations are W11-exclusive, it'll be fun watching some of the outlets who've defended sticking with W10 suddenly proclaim W11 is a necessity.
 

BorisTheBlade82

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@Exist50
To add even more to this mess: Not only will they have to decide on a per-game-level. They will have to decide on a per-thread-of-game level.
Is it even possible to address specific threads as in: This is a cache sensitive thread of Game x and that is a frequency sensitive thread of the same game?
 

Timorous

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Unbalanced cache on the dual CCD X3D products.

Seems like a precursor to having something akin to big little with Zen 5 where you have 8 Zen5 cores with v-cache and 16 Zen 5c cores without for the 8950X(3D).

Something I suggested yonks ago. So long as games are dumped onto the high cache CCD it should work fine.
 
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Exist50

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@Exist50
To add even more to this mess: Not only will they have to decide on a per-game-level. They will have to decide on a per-thread-of-game level.
Is it even possible to address specific threads as in: This is a cache sensitive thread of Game x and that is a frequency sensitive thread of the same game?
Even if it's possible, I doubt there's any benefit to per-thread CCX scheduling. As things stand, gaming shows a strong preference for all significant threads to be bound to the same CCX / L3 domain. I think the quick-and-dirty solution would be to simply bind whitelisted games/apps to the V-cache CCX and let anything else schedule freely (likely favoring the high frequency CCX).

I don't have any data to back this up, but I imagine it would often be better for a game to incorrectly bind to the non-Vcache CCX than to split its threads between the two.
 

coercitiv

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It's been talked about at length, but this naming scheme is absurd.
Who's affected by this? I don't like it either, having to retrain to prioritize for the third digit feels so random. But the average consumer doesn't care, just like they shouldn't care that half of Raptor Lake is using Adler Lake cores.
 
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BorisTheBlade82

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Even if it's possible, I doubt there's any benefit to per-thread CCX scheduling. As things stand, gaming shows a strong preference for all significant threads to be bound to the same CCX / L3 domain. I think the quick-and-dirty solution would be to simply bind whitelisted games/apps to the V-cache CCX and let anything else schedule freely (likely favoring the high frequency CCX).

I don't have any data to back this up, but I imagine it would often be better for a game to incorrectly bind to the non-Vcache CCX than to split its threads between the two.
Yeah, I think you are right. Hadn't thought about inter-thread communication.
 

Exist50

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Who's affected by this?
Anyone who buys old tech thinking it's new. I.e. anyone who doesn't follow this stuff as closely as we do.
But the average consumer doesn't care, just like they shouldn't care that half of Raptor Lake is using Adler Lake cores.
The average consumer would definitely notice the difference in performance, features, battery life, etc.

As for Raptor Lake, it's looking like only the desktop is true rebrands, but either way, at least higher number == better, and there're no significant feature differences. Of course, still not ideal, but not nearly this bad.
 

Timorous

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Even if it's possible, I doubt there's any benefit to per-thread CCX scheduling. As things stand, gaming shows a strong preference for all significant threads to be bound to the same CCX / L3 domain. I think the quick-and-dirty solution would be to simply bind whitelisted games/apps to the V-cache CCX and let anything else schedule freely (likely favoring the high frequency CCX).

I don't have any data to back this up, but I imagine it would often be better for a game to incorrectly bind to the non-Vcache CCX than to split its threads between the two.

If I was AMD I would have profiles in Ryzen Master to assign threads to the ideal CCD for certain workloads such as gaming.

That would mean CS:GO can be assigned to the high frequency CCD and MSFS can be assigned to the high cache CCD.

For stuff that scales beyond 8c it will be trickier to manage.
 

coercitiv

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The average consumer would definitely notice the difference in performance, features, battery life, etc.
We were talking about the naming scheme. When it comes down to performance / features / battery life, we would need to see the balance between perf numbers & prices.

As for Raptor Lake, it's looking like only the desktop is true rebrands, but either way, at least higher number == better
In the AMD naming scheme it's the same, higher number == better.

The really annoying part about AMD plan is the first digit, since they claim it signifies the year. If they run the first digit out of sync with the desktop platform, nasty things will happen in a couple of years. But then again, maybe they ditch the new scheme in less than that :tearsofjoy:
 

BorisTheBlade82

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Part 3 of the CnC Zen4 series:
This again confirms the IFoP bottlenecking RAM bandwidth - it was a questionable decision by AMD not to use wide-mode for single CCD SKUs.
 

biostud

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5ghz boost for 7800X3D while disappointing is still 500mhz over the 5800X3D and according to TPW the 13900K is only 6.2% faster than the 5800X3D at 1080p with an RTX 4090 in their 53 game benchmark. https://www.techpowerup.com/review/rtx-4090-53-games-core-i9-13900k-vs-ryzen-7-5800x3d/2.html
Will definitely wait for review now to decide which way to go. I did not expect such a huge reduction in frequency. Now it comes down to price and minimum fps. I will be GPU limited in anything I game, so I don't expect any difference on my system when it comes to max fps.
 

Harry_Wild

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AMD Expands Desktop Ryzen 7000 "Zen 4" Processor Family with 65W Models
by btarunr Yesterday, 20:31 Discuss (7 Comments)
Besides the sensational Ryzen 7000X3D processors taking the fight to Intel's "Raptor Lake," AMD expanded the desktop Ryzen 7000 even downwards, with the introduction of three new 65 W processor SKUs that include boxed stock coolers. These include the Ryzen 5 7600 6-core/12-thread, the Ryzen 7 7700 8-core/16-thread, and the Ryzen 9 7900 12-core/24-thread. There's no 16-core part in this segment. These processors come with TDP values set at just 65 W, and PPT values in the range of 90 W to 120 W, and so their clock speeds and maximum boost speeds are lower compared to the 7000X series, with more aggressive power-management.

The 7600 boosts up to 5.10 GHz, and packs a 65 W-capable Wraith Stealth boxed cooling solution. The 7700 boosts up to 5.30 GHz, and the 7900 up to 5.40 GHz. Both the 7700 and 7900 include a Wraith Prism RGB cooler that can handle thermal loads of up to 140 W. The three chips are priced lower than their 7000X series cousins, with the 7600 going for USD $229, the 7700 at $329, and the 7900 at $429. The three chips are drop-in compatible with existing Socket AM5 motherboards without needing any BIOS update.
 

eek2121

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Anyone who buys old tech thinking it's new. I.e. anyone who doesn't follow this stuff as closely as we do.

The average consumer would definitely notice the difference in performance, features, battery life, etc.

As for Raptor Lake, it's looking like only the desktop is true rebrands, but either way, at least higher number == better, and there're no significant feature differences. Of course, still not ideal, but not nearly this bad.
2023 Zen 2 is not OG Zen 2, so technically it IS a new product. The newer Zen 2 part will likely be faster thanks to LPDDR5 and possibly better clocks.

EDIT: looking back at the slides, it appears AMD is gimping the Zen 2 parts by giving them very little cache. Time will tell how that plays out.

Suffice to say, as long as a bigger model number is always faster, the naming scheme should not be confusing.
 

Timmah!

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ofc it does not make sense, its almost 100 percent fake.

I stand corrected, it was actually genuine. Surprised pikachu face.

That said, personally i am rather disappointed. It clearly comes with clock penalty once again, as seen on lower base clock and 5GHz top boost clock of 7800X3D. There will be no doubt lower all-core performance in the likes of Cinebench, Blender, etc... because of this.
Since the cache is only on the primary die, they can still claim that 5,7/5,6GHz boost on dual die models, but i have to wonder, when exactly will those cores boost to that frequency, since i presume in lower core count loads, when those frequencies are attainable, usually the cores on the primary chip are used. What if you run some app, that does not benefit from bigger cache, but would from higher clocks - how will the CPU know to run it on the non-vcache die to get that higher frequency? Unless you force it manually via Process Lasso or something. This looks pretty similar to Intel big.little situation, even if the cores are the same.

Ultimately, i need to see reviews, because the info we were given is wildly insufficient, too many questions. I still could return my 7950x till the end of January and get 7950x3D in February instead (would mean keeping everything in boxes for another month or 2), but i honestly dont know at this point, whether that would good idea. And the reviews probably wont come before February to help me decide.
 
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