Speculation: Ryzen 4000 series/Zen 3

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uzzi38

Platinum Member
Oct 16, 2019
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There is no weirdness.

What happens is that in ALL PCIe 3.0 boards, the 5500XT works @ x8 PCIe 3.0 while with X570 boards it works @ x8 PCIe 4.0. The difference stems from the fact that boards with PCIe 3.0 have HALF the bandwidth of X570 boards, that have PCIe 4.0.

Effectively, when you place ANY PCIe 4.0 card in a non-PCIE 4.0 board, you're bottlenecking the card's true performance. It the case of the 5700(XT) card(s) you don't notice it much because of the VRAM present in the card but you may notice in SOME games if you use a 5500(XT) card.
You missed the point. No GPU with 5500XT levels of performance should be bottlenecking even Gen3 x8. Even a 2080Ti can only barely do so, and it only looses like 1-2% performance with x8.
 

H T C

Senior member
Nov 7, 2018
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You missed the point. No GPU with 5500XT levels of performance should be bottlenecking even Gen3 x8. Even a 2080Ti can only barely do so, and it only looses like 1-2% performance with x8.

But that card has WAY more VRAM, specially VS the 4GB 5500XT models so the need for PCIe communication in VRAM saturation cases doesn't happen as often and thus doesn't become relevant. Not so with the 5500XT 4GB models.
 
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uzzi38

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But that card has WAY more VRAM, specially VS the 4GB 5500XT models so the need for PCIe communication in VRAM saturation cases doesn't happen as often and thus doesn't become relevant. Not so with the 5500XT 4GB models.
And yet even the 8GB model of the 5500XT saw a difference in performance from the switch from Gen 3 to Gen 4.
 

H T C

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Nov 7, 2018
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uzzi38

Platinum Member
Oct 16, 2019
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Yes, but significantly smaller when compared to the 4GB models.

EDIT

This is off topic: there is a topic about this already so i suggest we continue the discussion there. Don't have the link, though :(
But it shouldn't have seen one at all. See the problem?

In games where there was a noticable amount of CPU GPU communcation, it saw a difference even though it should have.

It's quite likely Navi 12 is aimed at workstations in an mGPU setup. Komachi doesn't think it's a mobile part, so considering the low clocks and HBM2 it's makes sense.

If that's what it's for, surely you can see how such an errata would need to be fixed, right?
 

Shivansps

Diamond Member
Sep 11, 2013
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There is no weirdness.

What happens is that in ALL PCIe 3.0 boards, the 5500XT works @ x8 PCIe 3.0 while with X570 boards it works @ x8 PCIe 4.0. The difference stems from the fact that boards with PCIe 3.0 have HALF the bandwidth of X570 boards, that have PCIe 4.0.

Effectively, when you place ANY PCIe 4.0 card in a non-PCIE 4.0 board, you're bottlenecking the card's true performance. It the case of the 5700(XT) card(s) you don't notice it much because of the VRAM present in the card but you may notice in SOME games if you use a 5500(XT) card.

Well if thats the case them using older bios on AMD boards from before the PCI-E 4.0 was forcely removed by AMD is an option for 5500 users... but you will be limited to older agesa.


You missed the point. No GPU with 5500XT levels of performance should be bottlenecking even Gen3 x8. Even a 2080Ti can only barely do so, and it only looses like 1-2% performance with x8.

its about the VRAM, with 4GB you will run short these days, this means there are still textures loaded on system RAM that the driver need to move to VRAM and from VRAM ro RAM constanly... This is not gona be needed on a 8GB card. This may explain the rather large perf gap of 4GB to 8GB.
 

Thunder 57

Platinum Member
Aug 19, 2007
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thigobr

Senior member
Sep 4, 2016
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I really hope that's true! I have decided to skip Ryzen 3000 altogether due to 3950X delays and shortages but looking good for an improved 16 core Zen3 next year!
 

burninatortech4

Senior member
Jan 29, 2014
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I really hope that's true! I have decided to skip Ryzen 3000 altogether due to 3950X delays and shortages but looking good for an improved 16 core Zen3 next year!

I'm in the same boat. Can't justify a one generation upgrade. Waiting to see what the 4700x/4900x brings to the table late 2020.
 

Elfear

Diamond Member
May 30, 2004
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I couldn't wait and jumped from a 1700 to a 2700X to a 3900X. The past 7-8yrs were so boring on the CPU front that I couldn't justify spending money on an annual basis but the last couple years have really got me excited with the massive IPC and core count increases. I'll gladly jump to a 4000-series chip if IPC gains are really in the 15-17% range.
 

DrMrLordX

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Apr 27, 2000
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17% IPC increase over Zen 2. They state 10-12% better integer performance and up to 50% better floating point. AVX 512?

Maybe, maybe not. Correct me if I'm wrong, but Zen1/Zen+ were 2x128b FMAC and Zen2 is 2x256b FMAC, correct? Zen3 may just be 4x256b FMAC though I would think that would give more than +50% performance in fp. That would hint at AVX512 support, but that wouldn't absolutely be necessary.
 

Saylick

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Sep 10, 2012
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dnavas

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Feb 25, 2017
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I honestly don't expect AVX 512.
The API, sure, the vector width, not so much. Even after this rumor. Otherwise it wouldn't be "50%". "Up to 50%" sounds more like a third FMA. Interesting that they didn't aim for Cascade Lake parity, but not completely surprising for all the reasons quoted above.
 
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lobz

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Feb 10, 2017
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I really hope that's true! I have decided to skip Ryzen 3000 altogether due to 3950X delays and shortages but looking good for an improved 16 core Zen3 next year!
It's almost sure that Ryzen 4000 will either come out @ holidays 2020 or 1H 2021.
 

Thunder 57

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Aug 19, 2007
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The API, sure, the vector width, not so much. Even after this rumor. Otherwise it wouldn't be "50%". "Up to 50%" sounds more like a third FMA. Interesting that they didn't aim for Cascade Lake parity, but not completely surprising for all the reasons quoted above.

So half-rate AVX 512 just like AVX with Zen 1? That sounds like a solid design choice.
 

lobz

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Feb 10, 2017
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Almost certain or just what you expect? I'm thinking back to school (August) if they try to rush it, or more likely September/October.
Zen 2 came out Q3 2019, consumer Zen 3 is practically impossible in Q3 2020, I'd say it's even improbable @ holidays 2020, but not impossible at least. There's also no reason for it, it's not like CML will be that huge of a threat on the desktop.
 

moinmoin

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Jun 1, 2017
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Maybe, maybe not. Correct me if I'm wrong, but Zen1/Zen+ were 2x128b FMAC and Zen2 is 2x256b FMAC, correct? Zen3 may just be 4x256b FMAC though I would think that would give more than +50% performance in fp. That would hint at AVX512 support, but that wouldn't absolutely be necessary.
Would be an odd intermediary step, but I could see Zen 3 with 3x256b FMAC and Zen 4 with 4x256b FMAC. The latter may need too much space to fit in 7nm+'s density improvement.

It's almost sure that Ryzen 4000 will either come out @ holidays 2020 or 1H 2021.
The pattern so far is a new Ryzen gen every 14 months.
 

Thunder 57

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Aug 19, 2007
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Zen 2 came out Q3 2019, consumer Zen 3 is practically impossible in Q3 2020, I'd say it's even improbable @ holidays 2020, but not impossible at least. There's also no reason for it, it's not like CML will be that huge of a threat on the desktop.

See what @moinmoin wrote. March '17. Refresh came April '18. Zen 2 came July '19. I expect the time between Zen+ and Zen 2 will be similar to that of Zen 2 and Zen 3. That puts it at September 2020. That's why I said August if they rush it for back to school sales, or more likely, September/October.

Also, I wouldn't be so sure that they "won't need it". The last time AMD got complacent was when they had K8 and got a bit lazy. We all know how badly that ended.
 

lobz

Platinum Member
Feb 10, 2017
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See what @moinmoin wrote. March '17. Refresh came April '18. Zen 2 came July '19. I expect the time between Zen+ and Zen 2 will be similar to that of Zen 2 and Zen 3. That puts it at September 2020. That's why I said August if they rush it for back to school sales, or more likely, September/October.

Also, I wouldn't be so sure that they "won't need it". The last time AMD got complacent was when they had K8 and got a bit lazy. We all know how badly that ended.
But you do realize, that the Ryzen 2000 series that came after 14 month, was not a new uarch, merely some optimizations plus a little bit better process? If I follow what @moinmoin said, Zen 3 would come 28 months after July 2019... of course it wont take that long, but I don't get you guys, maybe I'm dumb.