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

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Vattila

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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).

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! :)
 
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deasd

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beginner99

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Another data point on cutting out the heat by undervolting. 4.8ghz drops temps to 55C.

It's ironic. We went from CPUs that had huge headrom for overclocking right into factory OCed CPUs that any sane user will run either undervolted or otherwise TDP limited (eco mode).

I think this is a consequence of social media. Better to be on top of charts than to be efficient with headroom for OC.
 

eek2121

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I was wondering if TSMC has raised the prices on 5nm vs 7nm, when AMD is launching at same or lower prices. Do you think AMD has the same margins as zen3?
AMD is predicting their margins to be higher for the rest of the fiscal year, so I'm going to say they are improved.
No, you are right on that, but the issue with temperature reading is that it's essentially always maxed already whenever it would matter, so it's no longer a way to monitor if your chip is throttling due to the temperature limit. And unless you have strong cooling your chip at stock should be hitting the temperature limit way earlier than the PPT limit. To have any indication if and when that throttling due to temperature happens I suggested there should be some additional value to monitor from the Zen cores that shows how much they are adapting to the temperature (eventually leading to throttling).
PROCHOT should get triggered if your CPU were actually throttling. You can see whether this is the case in HWInfo64. You guys are totally hating on the thermal limits, but CPUs should be designed this way. That means there are no other (known) bottlenecks to keep things from scaling up. I am uncertain if the chips have any hidden hard limits (excluding LN2), but in theory, with unlimited cooling, all cores should be able to hit 5.8 GHz at once. In reality I suspect we'll never see that, of course. Maybe with a node shrink?
 

Kocicak

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It's ironic. We went from CPUs that had huge headrom for overclocking right into factory OCed CPUs that any sane user will run either undervolted or otherwise TDP limited (eco mode).

I think this is a consequence of social media. Better to be on top of charts than to be efficient with headroom for OC.

It is time to push efficiency charts in the foreground. Problem solved.
 

Timmah!

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Jul 24, 2010
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AMD subreddit has a deep view on air cooling


Looks like 4 pipes 120mm fan is enough to cool everything below 7900X when temperature limit is 95C.



What shock me is, he is patient enough that he even tested 2 pipes 80mm('WTF??!!'When I saw this) on a 7600X, and have a nice and unexpected result.

View attachment 68402

The hell are those clocks, i mean the 7950x. At this point i have seen/heard its 5,1GHz, 5,2Ghz, this one claims 5,05 and local review said 5,35 with 360 AIO.


I realize its cooling dependent, but when the difference is 300MHz between 2 measurements, supposedly on the same type of cooler, you start to wonder what is going on.
 

In2Photos

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Mar 21, 2007
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The hell are those clocks, i mean the 7950x. At this point i have seen/heard its 5,1GHz, 5,2Ghz, this one claims 5,05 and local review said 5,35 with 360 AIO.


I realize its cooling dependent, but when the difference is 300MHz between 2 measurements, supposedly on the same type of cooler, you start to wonder what is going on.
Ambient temps maybe? Dropping CPU temps by 1-2C can add a few 100MHz based on the boost algorithm is what it looks like to me. So if you start with room temps at 20C vs 22C vs 24C and so on that can affect the amount of headroom. Reviewers should always list ambient temps.
 

moinmoin

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It's ironic. We went from CPUs that had huge headrom for overclocking right into factory OCed CPUs that any sane user will run either undervolted or otherwise TDP limited (eco mode).
Technically it started with 3800X and 5800X. Those seemed an exception to the rule since AM4 was locked to 105W TDP/142W PPT as max at stock already. We were already talking about undervolting being the new overclocking at that point. With AM5 adding 170W TDP/230W PPT it's wild west for all chips including the top end (until some 24 or even 32 cores package appears that make more productive use of all the new headroom). With that the previous knowledge is even more useful now.

You guys are totally hating on the thermal limits
Considering this appears to come with a widespread ability to freely set the temperature limit in the BIOS I personally am actually loving it. I just want more benchmarks taken at lower temperature limits to see their impact (currently especially at what point ST gets affected).

I am uncertain if the chips have any hidden hard limits (excluding LN2), but in theory, with unlimited cooling, all cores should be able to hit 5.8 GHz at once.
We already know of the extreme overclocking to e.g. 6.45 GHz so around that's the theoretical limit. AIO obviously is far lower, but it combined with delidding might get some way closer.
 
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Timmah!

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Ambient temps maybe? Dropping CPU temps by 1-2C can add a few 100MHz based on the boost algorithm is what it looks like to me. So if you start with room temps at 20C vs 22C vs 24C and so on that can affect the amount of headroom. Reviewers should always list ambient temps.

I see. Did not consider that. Thank you!
 
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amrnuke

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It is time to push efficiency charts in the foreground. Problem solved.
Sure, then everyone will complain about the lack of progress in performance. Then you have to push performance charts to the foreground. Rinse. Repeat. (Kidding, of course...)

Zen is not marketed to the public for efficiency, it's marketed for performance. How do you think people would be reviewing the product if AMD chose to instead limit power draw and ended up being just equal to Alder Lake, in the name of efficiency? Seems to me it would be bad publicity, especially with Rocket Lake not even released yet.
 

Doug S

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I was wondering if TSMC has raised the prices on 5nm vs 7nm, when AMD is launching at same or lower prices. Do you think AMD has the same margins as zen3?

Per wafer prices for N5 are significantly (~80%) higher than N7 based on reports, so similar sized N5 dies are costing AMD a lot more. Those initial price "quotes" will have changed as processes mature so the percentage factor may no longer be accurate but N5 will always cost a lot more due to how many more layers are done with expensive EUV machines. There should be a more modest increase for N3 since N5 already had so many EUV layers there weren't as many more added (especially with N3E improving upon that vs N3)
 

deasd

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Zen4 dominating in Linux

If taking the geometric mean of all 333 benchmarks carried out under Linux, the AMD Ryzen 7 7700X came out even ahead of the Ryzen 9 5950X thanks to the mix of single and multi-threaded benchmarks. The Ryzen 7 7700X was also just behind the Intel Core i9 12900K Alder Lake processor with this large mix of benchmarks. Again, see the aforelinked OB result file for those wanting to dig through all 333 benchmarks in fine detail.

1.jpg
 

uzzi38

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Oct 16, 2019
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Ooh, there's something absolutely hilarious I'm dying to talk about and it involves Curve Optimiser. Outside of that thing, I have no clue.
So I completely forgot to come back to this.

So yeah the funny new CO feature?

iGPU curve optimiser. You can apply curve optimiser offsets to the single WGP.

You can't overclock it. But you can apply Curve Optimiser offsets.

Enjoy your completely useless yet funny new piece of info!

For video proof of this option in BIOSes see:


c6842651ee61bb0e96c2f1ff905a8282.jpg
 
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inf64

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Mar 11, 2011
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So I completely forgot to come back to this.

So yeah the funny new CO feature?

iGPU curve optimiser. You can apply curve optimiser offsets to the single WGP.

You can't overclock it. But you can apply Curve Optimiser offsets.

Enjoy your completely useless yet funny new piece of info!

Actually that guy's channel is awesome source of information, he describes how the boosting algorithm works at this timestamp:

At first his voice reminded of Buildzoid so I had to double check if it's him lol. Anyway, yet another great channel.

He has another video on how he hit 6Ghz on 7900X:
 

eek2121

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Aug 2, 2005
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The hell are those clocks, i mean the 7950x. At this point i have seen/heard its 5,1GHz, 5,2Ghz, this one claims 5,05 and local review said 5,35 with 360 AIO.


I realize its cooling dependent, but when the difference is 300MHz between 2 measurements, supposedly on the same type of cooler, you start to wonder what is going on.
Wait until you find out about the competition...
Hmm! Might be that AMD is aware of Intel's monolithic 34c Sapphire Rapids-X product and they're acting accordingly? RIP Threadripper 5995wx.
Threadripper Pro is how old now? That will likely be what AMD replaces first. Regardless, I don't blame them. While some are absolutely hating on Zen 4, Threadripper is going to be absolutely INSANE. If a 7950X needs 65W to roughly equal a 5950x, just imagine what Threadripper will bring. If AMD promised a MiniITX board of some kind, I would cancel my 7950X order for it...

...sadly, Zen 4 Threadripper will use a new socket.
 
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DAPUNISHER

Super Moderator CPU Forum Mod and Elite Member
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While some are absolutely hating on Zen 4,
Haters gonna Hate. It's fake news/disinformation campaign by the usual suspects. No one reading this should pay it any mind. The generational uplift is impressive. That is a fact.

The only criticism I personally have, is that it is a poor value for those of us that primarily use PCs for gaming. Skt 1700 owners will have the ability to drop in a bird of prey later if it has a nice uplift over 12th gen. AM4 owners can get fairly close to Zen4 with the 5800X 3D and keep their board and ram as well. Only scenario where it makes good budgeting sense, is if the gamer is coming from an old platform with DDR3 or slow DDR4, and wants to futureproof their new build as much as possible. That's why I am sitting this gen out. AM4 is doing everything I need, and Zen 5 or 6 will probably be here by the time I am ready to move on. Intel will only be in the discussion for me if they stop the 2 and your through tick tock nonsense with their Platforms. Or if AMD breaks their pledge to support AM5 into late '25 with 3 generations of CPUs.
 

PJVol

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May 25, 2020
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iGPU curve optimiser. You can apply curve optimiser offsets to the single WGP.
It's there since Cezanne. As for the rest, there's nothing really new, some "rebranded" or previously hidden "features" exposed here and there. Boring design actually ... ))
Hope Zen5 will be more exciting
Actually that guy's channel is awesome source of information
Yeah, glad he paid more attention to details this time gathering things together, unlike in the previous reviews (tried to convince him to do that in the comments :) )
 
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DrMrLordX

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Apr 27, 2000
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Threadripper Pro is how old now?

The 5995wx was launched in March. So seven months old? When you consider how long it took AMD to even get that chip onto the market, moving quickly to a Genoa/Zen4-based Threadripper Pro in under a year would be quite a change in AMD's HEDT policies.
 

biostud

Lifer
Feb 27, 2003
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Haters gonna Hate. It's fake news/disinformation campaign by the usual suspects. No one reading this should pay it any mind. The generational uplift is impressive. That is a fact.

The only criticism I personally have, is that it is a poor value for those of us that primarily use PCs for gaming. Skt 1700 owners will have the ability to drop in a bird of prey later if it has a nice uplift over 12th gen. AM4 owners can get fairly close to Zen4 with the 5800X 3D and keep their board and ram as well. Only scenario where it makes good budgeting sense, is if the gamer is coming from an old platform with DDR3 or slow DDR4, and wants to futureproof their new build as much as possible. That's why I am sitting this gen out. AM4 is doing everything I need, and Zen 5 or 6 will probably be here by the time I am ready to move on. Intel will only be in the discussion for me if they stop the 2 and your through tick tock nonsense with their Platforms. Or if AMD breaks their pledge to support AM5 into late '25 with 3 generations of CPUs.
In what gaming scenario is a RPL going to give you better performance than ADL, if you actually play modern games with high graphics settings?
Sure if you benchmark low settings and low resolution, but once we hit 1440p max graphics settings all zen3, zen4, ADL and probably RPL are within a few percent of each other in performance.