Speculation: Ryzen 4000 series/Zen 3

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soresu

Golden Member
Dec 19, 2014
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Maybe. Ultimately, the question is: what kind of iGPU will they put on Cezanne? Though I guess that's more applicable to a Zen5000 thread.
Probably Ryzen 5000HS/S/U, and likely RDNA2 - true, full fat RDNA2.

RDNA1 was at best a proof of concept filler to branch time between Vega and the full uArch benefiting from their console SoC design work.

I think proof of concept works best as a description, because it is not drastically superior to Vega while accompanying a very significant change in uArch to wave32 execution - this being the foundation on which RDNA2 is laid.

Perhaps RDNA1 even represents the early proof of concept shown to both MS and Sony, with later improvements going into both as well as divergent tech solutions developed for (and with) each console vendor.

The true RDNA2 on PC I believe represents the best of what they could get out of both projects, so as speculated it may well be superior to either solutions coming to consoles.
 
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mopardude87

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Oct 22, 2018
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I think it is safe to say that we will not see RDNA1 in any AMD APU, this generation or the next.
Shame so even with the 5000 series and perhaps ddr5 we won't have such a option? I think 5000 may have ddr5? Barely wrapping my head around the 3900x that is coming quite later this evening then expected, then the idea 4000 series may be another good drop in replacement then we got the 5000 series next year or 2022 at latest? So much excitement in so little time!
 

lobz

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Feb 10, 2017
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Shame so even with the 5000 series and perhaps ddr5 we won't have such a option? I think 5000 may have ddr5? Barely wrapping my head around the 3900x that is coming quite later this evening then expected, then the idea 4000 series may be another good drop in replacement then we got the 5000 series next year or 2022 at latest? So much excitement in so little time!
5000 series APUs (Zen 3) won't have DDR5 yet. Also he only meant RDNA1, ergo the next APU will either have a further optimized Vega or already RDNA2.
 
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mopardude87

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Oct 22, 2018
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5000 series APUs (Zen 3) won't have DDR5 yet. Also he only meant RDNA1, ergo the next APU will either have a further optimized Vega or already RDNA2.
Shame, i think it would be a absolute beast if it did. Well whatever APU ends up landing with DDR5 will be epic i think. I haven't followed Apus in a while but i got a friend who loves to run BOINC who is obsessed with them. MY htpc is turning into a 2500k/1070/1650 super before year is out so i got no need really for one myself.
 

soresu

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Dec 19, 2014
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If It won't happen then there is no reason to have more than 6-8CU RDNA2 or It will be bandwidth starved based on bandwidth of RDNA1 chips.
Do you mean quoted spec bandwidth or the actual bandwidth typically in use?

Because the 2 need not be the same thing, especially at lower resolutions.
 

Shivansps

Platinum Member
Sep 11, 2013
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LPDDR5 is already in some phones so the next APU planned for next year could(should) have support for LPDDR5. If It won't happen then there is no reason to have more than 6-8CU RDNA2 or It will be bandwidth starved based on bandwidth of RDNA1 chips.
That what i was thinking as well, anything that comes after Renoir will most likely have LPDDR5/DDR5 and probably be the first AMD Desktop DDR5/AM5 product. Maybe launching next year in notebooks and early 2022 in desktop.
 

Gideon

Senior member
Nov 27, 2007
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That what i was thinking as well, anything that comes after Renoir will most likely have LPDDR5/DDR5 and probably be the first AMD Desktop DDR5/AM5 product. Maybe launching next year in notebooks and early 2022 in desktop.
LPDDR5 and DDR5 are different enough that supporting one doesn't mean they will automatically support the other. Seriously, the name might be similar but "DDR5" is to "LPDDR5" what "car" is to "carpet".

I'm more than willing to believe they'll support LPDDR5. It would be nice if they'd also support DDR5, but considering that the standard still isn't finalised, I wouldn't be holding my breath ...
 

amrnuke

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Apr 24, 2019
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LPDDR5 and DDR5 are different enough that supporting one doesn't mean they will automatically support the other. Seriously, the name might be similar but "DDR5" is to "LPDDR5" what "car" is to "carpet".

I'm more than willing to believe they'll support LPDDR5. It would be nice if they'd also support DDR5, but considering that the standard still isn't finalised, I wouldn't be holding my breath ...
If they support LPDDR5 on Cezanne and exploit it, that means IF is going to need to be much faster, IIRC.

Is that's what AMD were getting on about with their Infinity Architecture? If so, this is something that may help close the inter-core and system RAM latency issues a bit even on Vermeer.
 

Valantar

Golden Member
Aug 26, 2014
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If they support LPDDR5 on Cezanne and exploit it, that means IF is going to need to be much faster, IIRC.

Is that's what AMD were getting on about with their Infinity Architecture? If so, this is something that may help close the inter-core and system RAM latency issues a bit even on Vermeer.
If you are alluding to the link between IF clock and DRAM clock those two are entirely decoupled in Renoir (partly for efficiency and likely partly to allow for faster LPDDR4X). I don't see any reason why they would go back on this even though different clocks between DRAM and IF has some performance implications.
 

tamz_msc

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Jan 5, 2017
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If you are alluding to the link between IF clock and DRAM clock those two are entirely decoupled in Renoir (partly for efficiency and likely partly to allow for faster LPDDR4X). I don't see any reason why they would go back on this even though different clocks between DRAM and IF has some performance implications.
They might be decoupled but there is still a limit to how high IF can clock in 1:1 mode, and 4266 MHz LPDDR4x doesn't actually run the IF at 2133 MHz - it runs at 1:2 mode at that speed.
 

NostaSeronx

Diamond Member
Sep 18, 2011
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They might be decoupled but there is still a limit to how high IF can clock in 1:1 mode, and 4266 MHz LPDDR4x doesn't actually run the IF at 2133 MHz - it runs at 1:2 mode at that speed.
Renoir doesn't appear to have a 1:1 mode.

.dram_speed_mts = 1600.0 => .fabricclk_mhz = 600.0
.dram_speed_mts = 2133.0 => .fabricclk_mhz = 1066.0
.dram_speed_mts = 4266.0 => .fabricclk_mhz = 1600.0

If it does follow the ratio at most it will be 2:1 and never 1:1 natively.

To support LPDDR5-6400 and keep the same ratio as the 1600/600 and 4266/1600 the fabric clock in Cezanne will need to be able to reach 2400. Which would also be enough to support DDR5-4800 at 2:1, and DDR5-6400 at ~2.66:1.
 
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DrMrLordX

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Apr 27, 2000
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Some boards will probably get UEFI updates to support Zen3. Expect some headaches or lost CPU support to accommodate firmware ROM size limitations.
 

uzzi38

Senior member
Oct 16, 2019
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Renoir doesn't appear to have a 1:1 mode.

.dram_speed_mts = 1600.0 => .fabricclk_mhz = 600.0
.dram_speed_mts = 2133.0 => .fabricclk_mhz = 1066.0
.dram_speed_mts = 4266.0 => .fabricclk_mhz = 1600.0

If it does follow the ratio at most it will be 2:1 and never 1:1 natively.

To support LPDDR5-6400 and keep the same ratio as the 1600/600 and 4266/1600 the fabric clock in Cezanne will need to be able to reach 2400. Which would also be enough to support DDR5-4800 at 2:1, and DDR5-6400 at ~2.66:1.
Yes it does, what are you on about?

1:1 mode is supported until:

DDR4-2666mhz on RNR-U
DDR4-3200 on RNR-H
 

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