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

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Vattila

Senior member
Oct 22, 2004
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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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Thunder 57

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Aug 19, 2007
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I'm curious about the performance of Zen 4 3D in games that use ray tracing. Raptor Lake has a huge performance lead over Zen 4 in heavy RT games like Spider-Man Miles Morales that use the CPU for BVH building and maintenance. Tests have it at nearly 50%.

The 3D cache should make a nice dent in that gap, but I doubt it will be enough to fully close it.

If I had $1 every time you posted this. If Intel was 50% behind, I bet you'd be blaming the game and calling it broken.
 

Harry_Wild

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Dec 14, 2012
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AMD Ryzen 7000 Series Desktop Line-Up
AnandTechCores
Threads
Base
Freq
Turbo
Freq
Memory
Support
L3
Cache
TDPMSRP
Ryzen 9 7950X16C / 32T4.5 GHz5.7 GHzDDR5-520064 MB170 W$699
Ryzen 9 7900X12C / 24T4.7 GHz5.6 GHzDDR5-520064 MB170 W$549
Ryzen 9 790012C / 24T3.6 GHz5.4 GHzDDR5-520064 MB65 W$429
Ryzen 7 7700X8C / 16T4.5 GHz5.4 GHzDDR5-520032 MB105 W$399
Ryzen 7 77008C / 16T3.6 GHz5.3 GHzDDR5-520032 MB65 W$329
Ryzen 5 7600X6C / 12T4.7 GHz5.3 GHzDDR5-520032 MB105 W$299
Ryzen 5 76006C / 12T3.8 GHz5.1 GHzDDR5-520032 MB65 W$229
 

Saylick

Diamond Member
Sep 10, 2012
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Thanks for posting the table. I added in the current AMD Store prices, if you don't mind. :D

AMD Ryzen 7000 Series Desktop Line-Up
AnandTechCores
Threads
Base
Freq
Turbo
Freq
Memory
Support
L3
Cache
TDPMSRPAMD Store Price
Ryzen 9 7950X16C / 32T4.5 GHz5.7 GHzDDR5-520064 MB170 W$699$574
Ryzen 9 7900X12C / 24T4.7 GHz5.6 GHzDDR5-520064 MB170 W$549$474
Ryzen 9 790012C / 24T3.6 GHz5.4 GHzDDR5-520064 MB65 W$429$429
Ryzen 7 7700X8C / 16T4.5 GHz5.4 GHzDDR5-520032 MB105 W$399$349
Ryzen 7 77008C / 16T3.6 GHz5.3 GHzDDR5-520032 MB65 W$329$329
Ryzen 5 7600X6C / 12T4.7 GHz5.3 GHzDDR5-520032 MB105 W$299$249
Ryzen 5 76006C / 12T3.8 GHz5.1 GHzDDR5-520032 MB65 W$229$229
 

Joe NYC

Platinum Member
Jun 26, 2021
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well, dont want to say expectation, but the “wish” was definitely for the CPU clocking as High as 7950x with 64 MB of vcache on each die. That would have been ideal.

instead, we are given sort of hybrid, with vcache on just single die, that has exactly the same downside as 5000 series, so the one thing we wished AMD to fix, the clock penalty, they clearly did not. So as a result we will have to rely on Windows to correctly schedule threads to proper ccds/cores. Thats hardly optimal, its added complexity that may cause issues.

Not to mention because of the lower clocks on the vcache ccd we may see lower scores in Cinebench and the likes, compared to vanilla 7950x, so 3d might not be always the best cpu.

So yes, its disappointing, because its not the ultimate CPU we wanted, but another trade-off, just bit more complex than 5800x3d was.

In general, I wish that AMD truly recognized the gaming market by selling a single CCD 7850x and 7850x3d with the highest binned parts.

Instead, these CPUs, 5800x, 7700x are a dumpster for worst binned parts. Which would not be a problem if there was also a highest binned part to go along with them for gamers.

We end up with counter-intuitive CPUs created by marketing, where 2 CCD CPUs, which have to split the thermal limit in half, have higher clock speeds than single CCD CPUs that have the full power and thermal envelope at their disposable. Which is all due to weird marketing / segmentation...

As far as the V-Cache versions of Zen 4, we are not really sure how much limitation is due to binning and how much is attributed to other areas / variables.
 

SK10H

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Jun 18, 2015
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well, dont want to say expectation, but the “wish” was definitely for the CPU clocking as High as 7950x with 64 MB of vcache on each die. That would have been ideal.

instead, we are given sort of hybrid, with vcache on just single die, that has exactly the same downside as 5000 series, so the one thing we wished AMD to fix, the clock penalty, they clearly did not. So as a result we will have to rely on Windows to correctly schedule threads to proper ccds/cores. Thats hardly optimal, its added complexity that may cause issues.

Not to mention because of the lower clocks on the vcache ccd we may see lower scores in Cinebench and the likes, compared to vanilla 7950x, so 3d might not be always the best cpu.

So yes, its disappointing, because its not the ultimate CPU we wanted, but another trade-off, just bit more complex than 5800x3d was.

From a 5800x owner standpoint having forced to upgrade to a x570 mb for zen3 in early days with 6 yr old Ram still, and having looked at the rumored 7900x3d spec before, it goes from a immediate purchase to a wait and see approach with these "lower than expected" reality.

I can easily justify the platform upgrade cost with 17% clock speed, 10% avg IPC, double vcache on the 6core chiplet for gaming workload at 20% bonus , at the speculated $549 price. It would also be OK if it was double vache @5.3 as well at a lower rumored expectations.

The unbalanced vcache is a little crappy with the 6 cores ccd, since games have 8 cores programmed in mind these days at least and the decision would be should it use a virtual core on vcache ccd or actual physical core on the non vcache. Vcache gaming was all about significantly improving the 1% fps latency so it doesn't chop, not so easy with the unbalanced approach when it ran out of threads.
More time to wait for getting cheaper ddr5 I guess. 😔
 

inf64

Diamond Member
Mar 11, 2011
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well, dont want to say expectation, but the “wish” was definitely for the CPU clocking as High as 7950x with 64 MB of vcache on each die. That would have been ideal.

instead, we are given sort of hybrid, with vcache on just single die, that has exactly the same downside as 5000 series, so the one thing we wished AMD to fix, the clock penalty, they clearly did not. So as a result we will have to rely on Windows to correctly schedule threads to proper ccds/cores. Thats hardly optimal, its added complexity that may cause issues.

Not to mention because of the lower clocks on the vcache ccd we may see lower scores in Cinebench and the likes, compared to vanilla 7950x, so 3d might not be always the best cpu.

So yes, its disappointing, because its not the ultimate CPU we wanted, but another trade-off, just bit more complex than 5800x3d was.
AMD addressed this in the PCWorld video. They did the simulations and saw the chip with two stacked Vcaches had marginal benefits Vs the one they are launching. The hypothetical SKU would have lower max boost/all core boost clocks and would generally underperform in non-gaming tasks with worse power/thermals while offering marginal benefits for gaming workloads. It makes perfect sense. Once we get more games to use >16 threads and Vcache not requiring noticeably lower clocks, it will be pointless to have SKUs with such configuration.

This leaves the door open for future hybrid SKUs as someone else mentioned in the Zen 5 thread : one CCD stacked with Vcache while the other using denser variants with 2x the core count and no Vcache.
 

Timmah!

Golden Member
Jul 24, 2010
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AMD addressed this in the PCWorld video. They did the simulations and saw the chip with two stacked Vcaches had marginal benefits Vs the one they are launching. The hypothetical SKU would have lower max boost/all core boost clocks and would generally underperform in non-gaming tasks with worse power/thermals while offering marginal benefits for gaming workloads. It makes perfect sense. Once we get more games to use >16 threads and Vcache not requiring noticeably lower clocks, it will be pointless to have SKUs with such configuration.

This leaves the door open for future hybrid SKUs as someone else mentioned in the Zen 5 thread : one CCD stacked with Vcache while the other using denser variants with 2x the core count and no Vcache.

yes, it would have had lower boost/clocks, cause they failed to fix the clock penalty issue. If they did manage to do it, you would be better off with both dies stacked and all cores being uniform, so there would be no need for any special scheduling.

As it is, this CPU looks to me more like 2x 8 core cpus than single 16 core. It still will be pretty good no doubt, and i will wait for reviews and all those questions answered (like all core clocks and performance), so i might change my mind as a result, but generally i am no fan of these hybrid designs, i got 7950x (still could return it and replace for x3d) over intel after 4 intel rigs since core2duo days, as i did not fancy little cores shenanigans, and while this is not the same, there are similarities, so i would be hypocritical to give this a pass.
 
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MadRat

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What stops AMD from simply remapping vcache at the system level? Instead of throwing 32MB of L3 evenly across 16 cores, what stops them from adjusting it on the fly? If they wanted to throw 32MB at core0, and withhold the rest from core1--> core15, that could really mess with benchmarks. Likewise, a core having little benefit from L3 shouldn't hold any hostage from the others.
 

poke01

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Mar 8, 2022
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Ugh, that guy spends more time posting bait tweets that are either pro-Intel or pro-Nvidia rather than tweets that promote his own software.

Also, I don't understand people's self-proclaimed responsibility for having to "keep AMD hype in check", especially when I don't really see the market as being heavily AMD favored to begin with, and not when AMD is still the underdog in terms of company size. I refuse to believe that a handful of Youtube leakers constitute the bastion of "over hyping" that he's trying to "correct".
Most of the hype that leakers say about AMD that is insane to begin with is about their upcoming GPUs.

"RDNA 3 will have better efficiency than Ada and performance too"

"91 TFLOP for Navi 31"

I hate leak culture for AMD. Nvidia leak hype is just to get negative clicks. "600 watt GPU" turns out the RTX 4090 is very efficient for the power it offers.

Also AMD is not an underdog anymore. They beat Intel in server CPUs and laptop/Ultrabooks when it comes to efficiency and actually release most of their products on time.

Their Market cap is now around 100 Billion and in 2015 it was 1 Billion.

AMD is not an underdog anymore it is a premium CPU brand and a high end GPU brand.

Nvidia is an high end/ultra high end GPU brand and Intel is the delay brand.
 
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Timmah!

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Jul 24, 2010
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Having little cores on a CPU is like having a bus full of handy gnomes with spades, they just rush out and get to work, you have to love them! :)

sorry, but meh. Would take 24c 2495x, if it was priced right, over “24c” 13900k, even if the latter is faster in single thread.
 

Timmah!

Golden Member
Jul 24, 2010
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Most of the hype that leakers say about AMD that is insane to begin with is about their upcoming GPUs.

"RDNA 3 will have better efficiency than Ada and performance too"

"91 TFLOP for Navi 31"

I hate leak culture for AMD. Nvidia leak hype is just to get negative clicks. "600 watt GPU" turns out the RTX 4090 is very efficient for the power it offers.

Also AMD is not an underdog anymore. They beat Intel in server CPUs and laptop/Ultrabooks when it comes to efficiency and actually release most of their products on time.

Their Market cap is now around 100 Billion and in 2015 it was 1 Billion.

AMD is not an underdog anymore it is a premium CPU brand and a high end GPU brand.

Nvidia is an high end/ultra high end GPU brand and Intel is the delay brand.

Nvidias aggressive and deceiving marketing is indeed deplorable, but i can attest the pro AMD fanboys among the leakers and so called “journalists” are equally annoying and terrible. There is very pro AMD local web, the main writer and admin likes to tell about himself how “objective” he is and no fan of any brand, when the exact opposite could not be more obvious. His latest “pearls” were that at fault of high Radeon prices this generation is the “pricing politics of Nvidia” and that for “CUDA” you are fine with way weaker card than 4090.…right, cause Huang actually sets AMD prices as well, and compute tasks via CUDA do not scale with more cores unlike games, so considering 4090 for productivity is not justified.

Absolute clown. I only saw this level of shilling aimed toward someone else than AMD (intel) from the Userbenchmark admin in the recent Zen4 controversy.
 
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Kaluan

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sorry, but meh. Would take 24c 2495x, if it was priced right, over “24c” 13900k, even if the latter is faster in single thread.
Well then, sorry to say friend but after this hybrid R9 79x0X3D fake debacle, I am even more convinced Granite Ridge (Ryzen 8000) will be hybrid chiplet (not big.LITTLE but fast.FASTER lol) as a baseline. 12th gen/Microsoft/Linux layed the ground work, now 7000X3D is tweaking it for it's needs so Ryzen 8000 will have the scheduling ecosystem.



Anyway, tough crowd when AMD seemingly prefects consumer chiplet and now stacking technology each gen, while their competition hasn't even gotten the former off the ground yet.

I'll hash it up to leaker syndrome.
We haven't even seen 3rd party data or prices and people insist on being disappointed.

Guess you can't always please both tech junkies AND consumers at the same time.
 

In2Photos

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Mar 21, 2007
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Anyway, tough crowd when AMD seemingly prefects consumer chiplet and now stacking technology each gen, while their competition hasn't even gotten the former off the ground yet.

I'll hash it up to leaker syndrome.
We haven't even seen 3rd party data or prices and people insist on being disappointed.

Guess you can't always please both tech junkies AND consumers at the same time.
Agreed. I find it interesting that people are saying AMD didn't "fix" the frequency issue when using vcache. "Fix" implies that is was broken to start with. It's merely a hardware limitation of something in it's infancy. And let's get mad at AMD because the rumors were wrong, after all they were the ones that started all the rumors right? Rumors should just be considered a "wish list".
 

Timmah!

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Jul 24, 2010
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Agreed. I find it interesting that people are saying AMD didn't "fix" the frequency issue when using vcache. "Fix" implies that is was broken to start with. It's merely a hardware limitation of something in it's infancy. And let's get mad at AMD because the rumors were wrong, after all they were the ones that started all the rumors right? Rumors should just be considered a "wish list".

does not matter how you call it, fix or not, its semantics. So they did not fail to fix it, they failed to bring it out of its infancy. Either way, its clearly not a feature.

personally, i mostly wonder how can it be a voltage issue, if the cpu can have different voltages for its different parts - i am pretty sure my skylake-x had separate voltages for core and uncore. I understood it was a problem with 5000 series, as there were maybe not pins on AM4 socket for this separate “voltage plane”, as vcache was not a thing, when AM4 was new, so they did not anticipate it, but AM5?
 

moinmoin

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7900X3D and 7950X3D turned out to be slightly awkward "have the cake and eat it too" packages, with the V-Cache CCD still being limited in frequency but now accompanied by an unhindered top end CCD.

So theoretically this product allows consumers to avoid making any tradeoff each separate choice would introduce.

In practice this hybrid design leads to plenty questions about feasibility with the scheduler used etc. Maybe a simple manual selector would be good to have.

The worst downside I see in this approach is that V-Cache allows the use of slower RAM but now doing so will hit the other CCD.
 
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In2Photos

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Mar 21, 2007
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7900X3D and 7950X3D turned out to be slightly awkward "have the cake and eat it too" packages, with the V-Cache CCD still being limited in frequency but now accompanied by an unhindered top end CCD.

So theoretically this product allows consumers to avoid making any tradeoff each separate choice would introduce.

In practice this hybrid design leads to plenty questions about feasibility with the scheduler used etc. Maybe a simple manual selector would be good to have.

The worst downside I see in this approach is that V-Cache allows the use of slower RAM but now doing so will hit the other CCD.
I don't think they are awkward, instead I feel like they provided the consumer with enough skus for you to make a choice based on the following scenarios.

Gaming only - 7800X3D
Productivity only - 7900X or 7950X
Mixed use - 7900X3D or 7950X3D

The only pushback seems to be about the core clocks being dialed back and lack of vcache on both CCDs. But where does a 7900X3D or 7950X3D with the same core clocks as the non X3D versions and double vcache really shine? What type of workloads? Seems like it would be very few use cases.
 

Dave3000

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Jan 10, 2011
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I wonder how the Windows 10, 11, and Linux thread schedulers will handle this for programs that favor larger L3 cache more than a little higher frequency and programs that favor a little higher frequency than more L3 cache or is it something that will have to be added to the scheduler and is if so, is it even possible?
 
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