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

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What do you expect with Zen 4?


  • Total voters
    330
  • Poll closed .

Exist50

Golden Member
Aug 18, 2016
1,694
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I think all of this talk of execution resources, buffer sizes, etc etc is all rather superfluous. GLC/RPC use significantly more transistors than Zen 4 (with higher power to match) yet doesn't have anything significant (IPC, meaningful frequency gap) to show for it. I think it's thus fair to conclude that GLC is bloated. The fact that they seem to be more or less reusing it until '24 doesn't make it look any better today. The opposite, if anything.
 

Hans Gruber

Golden Member
Dec 23, 2006
1,657
755
136
Can we talk about the non "X" Zen 4 7900 processor that is rated at 65w? Normally those would be 105w vs. the Zen 3 5900x. It says that it tops out @ 5.4ghz. Is anybody else interested in this CPU?
 
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coercitiv

Diamond Member
Jan 24, 2014
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Timorous

Golden Member
Oct 27, 2008
1,137
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There's no evidence for that particular change to Zen 4c.
It fits logically though.

current density of Zen 4 is 94M xtors / mm^2. At that density the Zen 4c CCD would be around 117mm^2 (based on 11B xtors which is 2x Zen4 with 2B removed because L3 cache is not doubled) which is just too big so density must be higher and not by a small amount either. Now you might argue it will be fewer transistors than that because clocks are going to be lower and it may be a bit lower but to hit 80mm^2 at 94M per mm^2 needs to CCD to be no more than 7.5B transistors. With 32MB cache that is just 5.5B transistors for 16c. It just does not look doable, at least not while still being called Zen4.

On Bergamo you may only have 8 CCDs to fit but you have twice the links because the IO die is connected to each CCX so rather than the 12 CCXs you have in Genoa you need links for 16 CCXs, more if there are 2 IO dies (which with Siena would make perfect sense, 1 for Siena for upto 64 cores and 2 for Bergamo for upto 128 cores) so they can talk to each other and act as 1.

What you get with APU transistor density is 11B fitting in 79mm^2 which seems far easier to fit for both Siena and Bergamo.

It also fits because the APU CCX has been designed, tested and is in production so re-using that block and just doubling them up gives you a huge head start in designing the Zen 4c CCD and is pretty standard for AMD to do given they like to use as much as possible as wide as possible.
 
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nicalandia

Platinum Member
Jan 10, 2019
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AMD 7000 Non-X Review by Anandtech is up..


1673273011405.png

1673273132447.png


TechpowerUp 7600 Review
AMD Ryzen 5 7600 Review - Affordable Zen 4 for the Masses

 
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Asterox

Senior member
May 15, 2012
973
1,658
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Approximate worst case scenario for a small stock Wraith Stealth CPU cooler, Cinebench R23. In gaming or mixed use, significantly lower temperatures and higher CPU All Core boost can be expected.

2023-01-09_155651.jpg

As expected, Wraith Prism RGB cpu cooler is very good for CPU-s with lower TDP.Again Cinebench R23, and what are the CPU temperatures in the classic CPU rendering test.

2023-01-09_160009.jpg

2023-01-09_160249.jpg
 
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yuri69

Senior member
Jul 16, 2013
236
332
136
Something is seriously off at AMD right now. Did they hire too many too quickly?
Nah, it seems to be more or less in line with the previous releases.

Early Zen 1s were replaced due to an errata causing segfaults.
Zen 2 era got boosting issues resulting in the meme "ABBA" version.
Zen 3 era got those endless USB port issues.

RDNA1 got endless stream of those black-screen reports.
Early RDNA2 got problems with power management.
RDNA 3 is... RDNA3.
 

eek2121

Platinum Member
Aug 2, 2005
2,292
2,996
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AMD 7900 vs 7900X vs 12900K vs 5950X

View attachment 74280


This has got to be the Most Efficient x86 CPU. 65W TDP beating not so old 12900K and 5950X

View attachment 74281
The 7950X is likely more efficient when run at lower power limits. I know it is a beast when TDP is set to 65W. AMD likely does not use the best dies with these non-X chips.
 

nicalandia

Platinum Member
Jan 10, 2019
2,955
4,557
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I would be very surprised if AMD just used APU desing(half L3) to get the space required to put 128 Cores worth of die area on the same package as Genoa.
 
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lopri

Elite Member
Jul 27, 2002
13,173
557
126
We have enough information already but let me add one more graph. Didn't Computerbase.de not too long ago publish a chart that showed 7700X, 7900X, and 7950X at same performance rating at 45W? I thought someone linked that chart here. This is a new chart apparently.

Computerbase.PNG
 
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Vattila

Senior member
Oct 22, 2004
771
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A while back in the thread, @Timmah! and I discussed the labelling design for the Ryzen processors (see post #7386).
Did AMD listen?

Label design comparison AMD Ryzen 5950X-7950X-7950X3D.jpg

In the latest design, seen in 7950X3D, note that they have made the font for "RYZEN" taller (also, the stroke width is reduced and corrected, for a lighter look and a more balanced "Y" in particular, which looked somewhat puny and out-of-place before). For the full product name, they have condensed the font and made the word spacing wider. For the product details, they now use a nicer condensed font. They have dropped "DIFFUSED IN TAIWAN" altogether, for less clutter. And the whole thing is nicer aligned.

Edit: I think it looks pretty nice now, but I still would want to get rid of the repetition and make the model number larger instead. While they keep using the tier number in the product name, which I think is awful (AMD even gets it wrong in keynote presentations), they could make it more distinct, e.g. by putting it in reverse. Something like this:

Proposed label design for AMD Ryzen 7950X.jpg

Note that I have reduced the size of the AMD logo slightly, so that the AMD arrow now sits centred above the "Z" in "RYZEN", as well as centred on the chip overall. I think this looks nicer and more balanced. I have moved the out-of-place "D" (for "demo sample", I presume) behind the SKU number, as to be less disruptive. Also note that the tier number is fittingly aligned below the "Y" (get it? Read vertically: "AMD, why 9?").
 
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StinkyPinky

Diamond Member
Jul 6, 2002
6,731
723
126
I feel like the 7900 makes the 7900X redundant. If you want more multi-threaded power then it's the 7950X anyway, and if you want a nice mix of cores and gaming on a lower budget the 7900 seems like the no brainer choice over the 7900X.
 

biostud

Lifer
Feb 27, 2003
17,103
2,982
126
I feel like the 7900 makes the 7900X redundant. If you want more multi-threaded power then it's the 7950X anyway, and if you want a nice mix of cores and gaming on a lower budget the 7900 seems like the no brainer choice over the 7900X.
Depending on were the retail price of the X processors go, there is no reason to get one over the none X parts.
 

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