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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Joe NYC

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View attachment 74004

Using the worst % examples given in the conference, for gaming the 7950X3D will be 13% faster than the 13900K. The 7800X3D at 21% faster than the 5800X3D, makes it 10% faster than the 13900K and probably equal to the KS in gaming.

Both will offer equally the fastest gaming performance. Productivity and pricing is where it becomes interesting.

If money is no object, the 7900X will probably be the best all around chip.

But, but, but...

How come there are no tuning benchmarks? How about tuned Raptor Lake with DDR-5 10,000 that can light up 2 seconds of BIOS boot screen?

We need more input on this from:

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Joe NYC

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I believe that the threads must be primarily assigned to die with cache for game threads and to bare die with other application, this does not seem difficult to do for me, but I know nothing about inner workings of an operating system, I wonder if AMD is working on some Windows update with Microsoft.

I think you are right.

If the scheduler evicts all of the non-game threads from the V-Cache CCD, then with those threads, all of the cashed memory those threads used will also be evicted.

Which would leave all of the L3 in V-Cache CCD for the use by the game.
 

Hail The Brain Slug

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I said it may trade blows in perfect circumstances, power limits be damned.

Nice word twisting though.

"with the 13900KS trading blows (when cranked up to 11 with fast RAM)."

Ah yes, word twisting. Could you clarify how what you said means "in perfect circumstances"? Sure seems to me like you're implicating it will trade blows only in some games and overall be slower, except that's not what you said.
 
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inf64

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I said it may trade blows in perfect circumstances, power limits be damned.

Nice word twisting though.
Well you did state that you expect the 13900KS to end up 10-15% faster than 13900K which makes little sense, to be honest. You might get ~4% clock boost with KS and that's it. Performance doesn't scale perfectly with clocks so 4% is the absolute best case scenario.
 
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JM Popaleetus

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"with the 13900KS trading blows (when cranked up to 11 with fast RAM)."

Ah yes, word twisting. Could you clarify how what you said means "in perfect circumstances"? Sure seems to me like you're implicating it will trade blows only in some games and overall be slower, except that's not what you said.
when cranked up to 11 with fast RAM

You even bolded, underlined, and italicized it. In the perfect nutty tuned circumstances that @Joe NYC mentioned.
 

Hail The Brain Slug

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when cranked up to 11 with fast RAM

You even bolded, underlined, and italicized it. In the perfect nutty tuned circumstances that @Joe NYC mentioned.

lol ok.

Since you want to move the goalposts so far away it's into high end enthusiast tuning territory, that claim is completely meaningless in the first place unless you're going to compare it to a heavily tuned Zen 4 3D chip. Which is enabled this time around.

You basically said nothing.

Heavily tuned processor is faster than stock processor, news at 11
 

JM Popaleetus

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Well you did state that you expect the 13900KS to end up 10-15% faster
I actually said I expect the 13900KS to be able to trade blows when cranked up to 11 with fast RAM as highlighted above.

I think tuned, with bleeding edge memory, power be damned, Raptor Lake may be able to throw a few punches back. Nothing that would make it a clear W.
 

Hail The Brain Slug

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I actually said I expect the 13900KS to be able to trade blows when cranked up to 11 with fast RAM as highlighted above.

I think tuned, with bleeding edge memory, power be damned, Raptor Lake may be able to throw a few punches back. Nothing that would make it a clear W.

Just quit now.

JM Popaleetus said:
roughly 10-15% on average faster than the 13900K in 1080p
 

PJVol

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So they don't seem to have solved the V/F problem for 3D stacked CCD, basically the same 400MHz deficit as with the 5800x3d.
And given the most of the Zen3->Zen4 performance uplift came from higher clock speeds, this doesn't bode well for 7800x3d. Let's see what they squeeze out of the "hybrid approach" in 2CCD models.
All in all, dissapointing so far.

Capping the 7700X at 5000mhz might give us an idea of 7800x3d performance in non-gaming scenarios.
 
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JM Popaleetus

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Just quit now.
In my very first post, I stated "I imagine the 13900KS will be 5-10% better than the K and again about equal in gaming due to brute force."

Probably closer to the 5%. Nonetheless, what part of brute force, and my offhand remark of "when cranked up to 11 with fast RAM" are you not understanding?

roughly 10-15% on average faster than the 13900K in 1080p

That statement was clearly in reference to the X3D chips. I did not intend the latter half of that sentence to imply the KS will ALSO be 10-15% overall faster. I clearly said otherwise prior. I just foresee it being able to trade blows in select circumstances.

You basically said nothing.

Heavily tuned processor is faster than stock processor, news at 11
I'd argue that's what the KS is. A factory heavily tuned processor.
 
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Hail The Brain Slug

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In my very first post, I stated "I imagine the 13900KS will be 5-10% better than the K and again about equal in gaming due to brute force."

Probably closer to the 5%. Nonetheless, what part of brute force, and my offhand remark of "when cranked up to 11 with fast RAM" are you not understanding?



That statement was clearly in reference to the X3D chips. I did not intend the latter half of that sentence to imply the KS will ALSO be 10-15% overall faster. I clearly said otherwise prior. I just foresee it being able to trade blows in select circumstances.

You said both will be 10-15% faster. Nowhere did you say 5-10% for 13900KS.

Also what part of "making a claim about how well a heavily overclocked/tuned product can perform relative to stock products" is a totally meaningless statement don't you understand?
 
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Kocicak

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So they don't seem to have solved the V/F problem for 3D stacked CCD, basically the same 400MHz deficit as with the 5800x3d.
And given the most of the Zen3->Zen4 performance uplift came from higher clock speeds, this doesn't bode well for 7800x3d. Let's see what they squeeze out of the "hybrid approach" in 2CCD models.
All in all, dissapointing so far.
I think that is mostly thermal issue. The dies are just slapped together and the electrical connections are touching each other, there is no solder interface. I think that avoiding too much heat production in the CPU die is there to avoid too much thermal expansion/contraction and corrupting the connections.
 

Hail The Brain Slug

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I think that it is mostly thermal issue. The dies are just slapped together and the electrical connections are touching each other, there is no solder interface. I think that avoiding too much heat production in the CPU die is there to avoid too much thermal expansion/contraction and corrupting the connections.

I saw somewhere that the stacked die can do up to 1.4V which is an improvement from Zen 3D, which was limited to 1.35V. Not a big improvement, but an improvement nonetheless.

I do see single core boost VID going as high as 1.465v on my 7950X, so it makes sense at 1.4V there is some boost headroom lost. Less headroom lost when compared to 5950X 1.5 VID for 4.9 GHz vs. the 1.35V max for the 5800X3D, so there's probably a fair amount of extra performance to squeeze out with PBO and CO for those willing to put forth that effort.
 

Joe NYC

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So they don't seem to have solved the V/F problem for 3D stacked CCD, basically the same 400MHz deficit as with the 5800x3d.
And given the most of the Zen3->Zen4 performance uplift came from higher clock speeds, this doesn't bode well for 7800x3d. Let's see what they squeeze out of the "hybrid approach" in 2CCD models.
All in all, dissapointing so far.

Tough crowd here. The best gaming CPU is "disappointing".
 

Kocicak

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Tough crowd here. The best gaming CPU is "disappointing".
What do you mean? 7950X3D is the best. 7800X3D is fully cushioned by the cash, which robs both ST and MT performance from it. Dual chiplet CPUs can still run that naked chiplet quickly not losing any ST or low thread count non gaming performance.
 

Dave3000

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If the 7900X3D and 7950X3D do end up getting one normal CCD and a 3D V-cached CCD with lower frequency, would a program such as Process Lasso be beneficial for gaming in that situation? In Process Lasso assign the cores of the 3D V-cached CCD to games that benefit more from the larger cache than the higher frequency normal CCD and assign the cores of the normal CCD to games that benefit more from the higher frequency than the larger cache? Still you would have to know much each game on a individual basis benefits from larger L3 cache vs higher frequency for the optimal gaming performance on these two CPU's?
 
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JM Popaleetus

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I guess if you just want to spam posts with differing info, that's your perogative. I was directly quoting you explicitly saying 10-15%. Denying you said that is on you.
You clearly don't want to have an actual discussion, but I made four predictions across two posts.
  1. The 7800X3D and 7950X3D will be roughly equal in gaming.
  2. The 7800 X3D and 7950X3D will average 10-15% faster than the 13900K, again in gaming. And obviously when not GPU bound.
  3. The 13900KS will be 5-10% faster than the K.
  4. The KS may trade blows with the X3D when "when cranked up to 11 with fast RAM".
The third I agree will be closer to the 5%. The fourth, I thought it was clear I meant at 720P in certain games, with DDR5-8000 and TDP be damned.

I very well may have worded my posts initial poorly, but you're the one continuing to harp on the latter-half of that one post as if it was gospel.

So again, good day. This was a fun way to occupy the waste of time that was my Zoom meeting.