Discussion AMD Cezanne/Zen 3 APU Speculation and Discussion

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dr1337

Senior member
May 25, 2020
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Fresh leak out today, not much is known but at least 8cu's is confirmed. Probably an engineering sample, core count is unknown and clocks may not be final.

This is very interesting to me because cezanne is seemingly 8cu only, and it seems unlikely to me that AMD could squeeze any more performance out of vega. A cpu only upgrade of renoir may be lackluster compared to tigerlake's quite large GPU.

What do you guys think? Will zen 3 be a large enough improvement in APU form? Will it have full cache? Are there more than 8cus? Has AMD truly evolved vega yet again or is it more like rdna?
 

LightningZ71

Golden Member
Mar 10, 2017
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That followup video is certainly interesting, but also expected. If they are good ng to test ram that is above spec for the processor (3200) and run it at rated speed, they should have tried overclocking the iGPU at the same time. In my experience, the 3400g did it's best when a moderate iGPU overclock was combined with overclocker ram.

No, I don't expect miracles.
 

Shivansps

Diamond Member
Sep 11, 2013
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The 3400G is a special case because it has a lot of shaders (more than low end dgpus) but it is held back by low freq, so with a 200mhz overclock it gets interesting. If you have dual rank DDR4-3200 or DDR4-3466.

I think it was OK, comparing the 3400G OC vs the 5700G stock would have been unfair, and the 5700G would have gained nothing from OC with those rams.
 
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Shivansps

Diamond Member
Sep 11, 2013
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I already have in my hands a 5600G, im starting to think this APU launch may be diferent because i only remember AMD making sure there is APU stock worldwide for Picasso, generally we need to wait like a month until the new stuff starts to arrive.

aJhFaRf.png


ill see on monday what it can do.
 

Shivansps

Diamond Member
Sep 11, 2013
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ill post results probably tomorrow. One thing i can say for sure is that Hardware Unboxed was spot on with the memory, dual rank is the way to go, everything that is 3200 or faster will perform too close to each other, not worth the money. Dual rank, or use 4 single rank sticks. I only had one dual rank 3200 kit, and for a short while today, after that i started using 2, 2x8 DDR4-3600 kits, that was the faster combination, faster than DDR4-4000 single rank. Oh, DDR4-4000 is the max you can use, after that it goes async and performance drops.

As for overcloking, 2300 is the max i could get stable, and to be honest it is not worth it either, just as with the ram, it gives very little gains, but it really helps on some games that drop below 30, like Cyberpunk.

The rest is petty much the same as always, relive is not enabled on adrenaline control panel and at this point i dont think it is ever coming back, it was taken away like what? 2 years ago?

One thing i did discover, and i cant belive im discovering right now, is how the VRAM works, AMD always have the 2GB dynamic regardless of what you set on the bios, this i think we all know, the part i did not know is that that comes ON TOP of wharever you set on the bios, so if you set 512MB on bios (thats the default auto value for Asus), it is 512MB+2GB and this is a non issue most of the time, yet today a discovered a exception with two games that work in exact opposite ways, RDR2 and Jedi Fallen Order, JFO was refusing to use the dynamic vram it was only using the 512MB what resulted on on textures not loading properly. I fixed this by setting manually 2GB on bios.
RDR2 works the opposite way, it only ever uses the dynamic vram, so if you set 2GB manually, it is never used and that memory is wasted. And that causes it to crash on the benchmark with 16GB when attemping to use more than 13GB of ram.

As for manually choosing the VRAM, on Asus enabling resize bar(i think it is about enabling "Above 4G Decoding" than bar itself) allows more than 2G of VRAM to be selected, up to 50% of total ram, 8G is avalible with 16GB RAM and 16G with 32GB RAM, selecting 8GB is actually very funny because RDR2 would use NONE OF IT, and Shadow of the Tomb Raider loads up to 6GB!!!

And yeah, 8GB vram, i also ran the eth miner on it, luckily, it is a crappy 4 mh/s on the faster 4xDDR4-3600 configuration with the Vega 7 at 2300mhz.

as a bonus ill leave here the screen of Shadow of the Tomb Raider using 6GB VRAM on the APU.
7VyL2zl.png
 
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LightningZ71

Golden Member
Mar 10, 2017
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Just that one screenshot tells it's own story. The iGPU is clocking at 2300mhz and is seeing 99% utilization with the 3600mhz ram. The system is certainly iGPU capability starved at this point. It's likely that the 5700g with it's additional CU wouldn't see a significant improvement over this, even when clocked to the same level. That's only about 15% more gpu grunt, which might get you about 3-5 more frames at most.

This really does support Shivas' point that Vega on Renoir/Cezanne was shrunk too much. It might be barely sufficient on mobile, with the usually more constrained ram configurations, but it's not doing the desktop APUs any favors at all. I hope that the next generation of APUs on mobile get far more generous configurations. Having significantly more bandwidth and interleaving of transfers on DDR5 should justify at least 8 CUs of RDNA2 (16 Vega equivalents).
 

QueBert

Lifer
Jan 6, 2002
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I would love to test out one of these, I just got a laptop with a 5700u last month and the apu's really impressed me so far. And I know since it's Zen2+ the Zen3 ones would perform a decent amount better. 900p on my 13.3" screen's fine with me. Since integrated graphics came into existence, I remember them always being junk for gaming unless it was super old ones. Apparently, you can play Cyberpunk 2077 on a 5700U with low'ish, but playable framerates, which is absolutely crazy shit to me lol. Will probably upgrade to a 5800U laptop when they're actually available.
 

Insert_Nickname

Diamond Member
May 6, 2012
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ill post results probably tomorrow. One thing i can say for sure is that Hardware Unboxed was spot on with the memory, dual rank is the way to go, everything that is 3200 or faster will perform too close to each other, not worth the money. Dual rank, or use 4 single rank sticks. I only had one dual rank 3200 kit, and for a short while today, after that i started using 2, 2x8 DDR4-3600 kits, that was the faster combination, faster than DDR4-4000 single rank. Oh, DDR4-4000 is the max you can use, after that it goes async and performance drops.

Have you tried triple or quad rank? I'd be interested in how that performs compared to regular dual rank. You may not be able to get much more then 3000MHz'ish out of it, but it should perform very well in practice. Nobody ever seems to test that.

AMD CPU/APUs have always loved dual rank memory. So I'm not surprised it performs well on Cezanne. I'm running triple rank (16+8GB on each channel) on my 3600 at 3066MHz, it's a nice compromise between speed and the number of ranks.
 

Shivansps

Diamond Member
Sep 11, 2013
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Have you tried triple or quad rank? I'd be interested in how that performs compared to regular dual rank. You may not be able to get much more then 3000MHz'ish out of it, but it should perform very well in practice. Nobody ever seems to test that.

AMD CPU/APUs have always loved dual rank memory. So I'm not surprised it performs well on Cezanne. I'm running triple rank (16+8GB on each channel) on my 3600 at 3066MHz, it's a nice compromise between speed and the number of ranks.

The thing is i dont have two fast 16GB sticks to test unfortunately, i cant just go and take wharever ram i want. So i only had 8GB sticks and they are all single rank these days, unless someone have a old kit laying around with 2R 8GB sticks, this is going to be the case for everyone running Cezanne, so, going 4 ranks means going to 32GB.

I tested:
-2x8 DDR4-3200 (2R) + IGPU Stock
-2x8 DDR4-3200 (2R) + IGPU OC
-2x8 DDR4-3466 (2R) + IGPU Stock
-2x8 DDR4-3466 (2R) + IGPU OC
-2x8 DDR4-3600 (2R) + IGPU OC
-2x8 DDR4-4000 (2R) + IGPU OC
-4x8 DDR4-3600 (4R) + IGPU Stock
-4x8 DDR4-3600 (4R) + IGPU OC
 

NTMBK

Lifer
Nov 14, 2011
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This really does support Shivas' point that Vega on Renoir/Cezanne was shrunk too much. It might be barely sufficient on mobile, with the usually more constrained ram configurations, but it's not doing the desktop APUs any favors at all. I hope that the next generation of APUs on mobile get far more generous configurations. Having significantly more bandwidth and interleaving of transfers on DDR5 should justify at least 8 CUs of RDNA2 (16 Vega equivalents).

The market doesn't really care about desktop APU performance. If you want graphics power, you put in a GPU.

It's massively important in a power, heat, and size constrained laptop, so that is rightly where they put the effort. On desktop they just need it to work well enough for non-gaming systems.
 

Abwx

Lifer
Apr 2, 2011
10,847
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5600G and 5700G review :


With a specific review for the iGPU :

 

Shivansps

Diamond Member
Sep 11, 2013
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Looks like Computerbase reached to the same opinion as i, DDR4-4000(the max you can use) is faster, but not worth it with these IGPs. The same with the OC potential, its there, but it does very little...

But it is definatelly worth it to use faster than DDR4-3200(DDR4-3466 or 3600 is what i would recomend) AND OC at the same time, it is not a big jump but having both it helps a lot to keep some games over 30.

As for the other thing, lets not start that again, Computerbase is right to point out these APU are around 30% below the RX 460, just think about what could have been. Now AMD is going big again with RMB, no point in arguing this, wharever the reason for the shrunk on Renoir, they are now undoing it.
 
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maddie

Diamond Member
Jul 18, 2010
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Looks like Computerbase reached to the same opinion as i, DDR4-4000(the max you can use) is faster, but not worth it with these IGPs. The same with the OC potential, its there, but it does very little...

But it is definatelly worth it to use faster than DDR4-3200(DDR4-3466 or 3600 is what i would recomend) AND OC at the same time, it is not a big jump but having both it helps a lot to keep some games over 30.

As for the other thing, lets not start that again, Computerbase is right to point out these APU are around 30% below the RX 460, just think about what could have been. Now AMD is going big again with RMB, no point in arguing this.
What are you on about again?

All I see is strong evidence that dual channel DDR4 is a roadblock to iGPU performance gains, barring an infinity cache solution.
 
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LightningZ71

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With stacking, that's not impossible. That being said, the improvement in ram efficiency in RDNA, combined with the higher bandwidth and greater utilization of it in DDR5, should make even a modestly expanded iGPU achieve similar performance to an RX560. At 1080p, that's not bad, and it won't even require an infinity cache setup.

One thing that is absolutely holding back the APUs is the L3 size. Doubling it again should make a big difference all-around, and with N5, that's not impossible.
 

blckgrffn

Diamond Member
May 1, 2003
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www.teamjuchems.com
With stacking, that's not impossible. That being said, the improvement in ram efficiency in RDNA, combined with the higher bandwidth and greater utilization of it in DDR5, should make even a modestly expanded iGPU achieve similar performance to an RX560. At 1080p, that's not bad, and it won't even require an infinity cache setup.

One thing that is absolutely holding back the APUs is the L3 size. Doubling it again should make a big difference all-around, and with N5, that's not impossible.

Having used an RX460 at 1080p I can tell you that's not a very satisfying bar to clear, especially heading in 2022. Let alone heading into, what 2023, when we actually see N5 APUs?

I hear what you are saying, but the ~35% or so increase in bandwidth moving to DDR5 is "meh" compared to what the IC could do when coupled with that same bandwidth at 1080p. We'll see what the 6600XT can do with it.

FSR like tech is probably going to be key to many titles and 1080p APU performance in AAA titles... probably indefinitely? I am sure that AMD likes selling GPUs too.
 
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NTMBK

Lifer
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Well . . . some downmarket consumers do. They don't bring as much cash to the table, so under the present circumstances where dice need to be sold at a premium, their needs will not be met first (or perhaps at all).

Is it worth compromising the design of a laptop part to suit that tiny, low profit niche? I suspect not.
 

Shivansps

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Sep 11, 2013
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What are you on about again?

All I see is strong evidence that dual channel DDR4 is a roadblock to iGPU performance gains, barring an infinity cache solution.

How do you explain that the 5700G is faster than the 5600G in IGP then? Check Computerbase numbers, they used 2x8 DDR4-3200 what is the worst possible option for bandwidth, and the 5700G is still ahead. It does not means you are not going to gain FPS with faster ram or dual rank sticks, you do, but it is not as much as you may think, the 5700G has a lead, small, but still a lead, specially considering it should also gain more from faster ram.
 

maddie

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Jul 18, 2010
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How do you explain that the 5700G is faster than the 5600G in IGP then? Check Computerbase numbers, they used 2x8 DDR4-3200 what is the worst possible option for bandwidth, and the 5700G is still ahead. It does not means you are not going to gain FPS with faster ram or dual rank sticks, you do, but it is not as much as you may think, the 5700G has a lead, small, but still a lead, specially considering it should also gain more from faster ram.
Tiny disproportionate gains really is grasping at straws. The RX 560 is about 50-75% faster than this APU. Do you really see that performance easily achievable with DDR4? For any meaningful increase in APU graphics performance, there has to be a way to significantly increase effective memory access, either through increased raw memory bandwidth ( high speed DDR5, Quad channel memory) or through caching mechanisms, such as the recently introduced infinity cache ( probably best choice).

Expecting large gains by doing more of the same is wishful thinking in my opinion.
 
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Shivansps

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Tiny disproportionate gains really is grasping at straws. The RX 560 is about 50-75% faster than this APU. Do you really see that performance easily achievable with DDR4? For any meaningful increase in APU graphics performance, there has to be a way to significantly increase effective memory access, either through increased raw memory bandwidth ( high speed DDR5, Quad channel memory) or through caching mechanisms, such as the recently introduced infinity cache ( probably best choice).

Expecting large gains by doing more of the same is wishful thinking in my opinion.

I only said RX 460, but look at this, im going to put all data on a graph later, but this does not looks like ONLY memory bound to me:

DDR4-3200 w/IGP STOCK
Jod5ehr.png

DDR4-3200 w/IGP OC
ulawe4O.png

DDR4-4000 w/IGP OC
lbD0LAY.png

4xDDR4-3600 w/IGP OC
WUPrwZZ.png

4xDDR4-3600 w/IGP STOCK
dv41iDC.png
 
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DrMrLordX

Lifer
Apr 27, 2000
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Is it worth compromising the design of a laptop part to suit that tiny, low profit niche? I suspect not.

Low profit, probably, tiny niche, not really. The world is a much bigger place than the US or Europe and silicon shortages won't last forever.

I'm inclined to agree with @maddie . Eventually AMD will find themselves with access to N7/N6 wafers and a shrinking family of products that need it. That day is not today, though.
 
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Abwx

Lifer
Apr 2, 2011
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I'm inclined to agree with @maddie . Eventually AMD will find themselves with access to N7/N6 wafers and a shrinking family of products that need it. That day is not today, though.

5700G die is 180 mm2, not sure what need to be shrinked since they can get something like 320 functional dies out of a waffer, dunno the exact waffer cost but seems that it got below 8000$ when Vermeer was released.

11-630.c1597b03.jpg