Speculation: Ryzen 4000 series/Zen 3

Page 126 - Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.

moinmoin

Golden Member
Jun 1, 2017
1,611
1,508
106
@moinmoin, you are conflating AMD last year with AMD three+ years ago.
And you think what you propose AMD did was done within last year?

When Zen hit the market, AMD was deep in the WSA with GloFo, who had been chronically behind other foundries.
Still is until spring next year when the WSA finally runs out.

They were just barely working with TSMC at the time.
That's wrong. AMD actually has a long history working with TSMC thanks to their GPUs and semi custom business.

I have no problem believing that AMD will have something being produced at full rate on N5P in the fourth quarter of this year. I personally think that it is going to be a zen 3 CCD. I don’t think that there will be a 5nm APU in HVP until 1H21.
There may be a GPU pipecleaner on N5P in 4Q. I consider anything CPU an impossibility this early time wise. APUs are even further off.
 
Mar 11, 2004
20,008
2,232
126
Going to chime in with my 2¢. This N5P rumor seems like 100% BS, and I'm honestly confused why so many are taking it seriously. AMD needs to deliver on their roadmap as close as possible to be seen as a more reliable alternative to Intel, and thus pull away marketshare. They will have a substantial PnP and cost advantage even without 5nm, and they have a relatively small team and limited resources. Why on earth would they risk it all to be the first customer on a bleeding edge process? Best case scenario, they suffer a ~1 quarter delay to have an even more substantial lead over Intel. Worst case scenario, that stretches a few more quarters. At some point, they also run the risk of intersecting with Sapphire Rapids, which would eliminate any relative performance advantage 5nm would have given them.

No, Zen 3 will be on some variant of 7nm. Possibly 7+, but more likely 7P.
We're 2-3 months into stay-at-home. Speculation has never been in short supply. And us enthusiasts have always salivated over these scenarios. Look back at Athlon 64, then A64 X2, then Core 2 Duo, Sandy Bridge, then Zen 2. There's ample excitement for Zen in general, so people are going to get excited for juicy "what if" thinking.

Who to say this is in anyway impacting their reliability? You think OEMs are gonna be mad if AMD offers them much better product that likely won't require much if any extra effort on their part to support? Without knowing the timetable, its tough to say it'll be problematic much if at all for AMD's partners, for all we know it might actually suit their timetables better. AMD also has to prove that they can reliably advance things, they have to show they can offer performance worth building product lines for. Better AMD products makes the sell easier for their partners. Also, don't forget, AMD is still the underdog here.

Risk it all? They were already developing for that process, and they've been working well with TSMC and there hasn't been much indicating 5nm isn't going well too, and its provided a situation where both could benefit. It doesn't sound that risky, and it could potentially have big payoff. I think its riskier for AMD not to push. Heck, this is helping one of their partners, as TSMC isn't going to want production capacity going unused. This has other ramifications too, as when capacity opens up at TSMC or planning future production, AMD will likely be one of the first ones they'll call. And when AMD needs/wants something, TSMC will probably be willing to do what they can. I think there might be other potential future ramifications that could be pretty huge (look at the announcement about the TSMC fab in the US) as well.

It does? So should Intel have called it "Chaos rapids" since it'll drown Zen? I don't understand that at all though, as how would releasing a worse Zen 3 earlier help them deal with such a chip? So they'd get some sales before Intel kills them? Or would they be better off having a better performing chip to compete better with stronger Intel offerings?

Now, don't get me wrong, I'm not treating this like its true and totally happening. and I'm just having fun speculating. I don't even really have a problem with your rationlizations (I think they're sound), I just wanted to offer some counter rationale.
 

Hans Gruber

Senior member
Dec 23, 2006
893
236
116
I think the Zen2+ chips that have leaked @ 1.2v and 2-300mhz faster than normal Zen2 is probably done on the enhanced 7nm silicon that Zen3 will be using. An early test run of the silicon probably because they had extra wafers. The same could be true about 5nm on Zen3 or at least a plan for it. A test run but obviously not intended for Zen 3 until a year after Zen3 is released on the enhanced 7nm process.
 

Shivansps

Platinum Member
Sep 11, 2013
2,844
612
136
Just saw this leak with Fire Strike scores of Renoir APUs.





Ok the DDR4-3200 limitation is clear here, but the graphics scores look a little low to me, 3576 for the 4200G stock? ist that around the same the 3200G can do at stock?

 
  • Like
Reactions: lightmanek

LightningZ71

Senior member
Mar 10, 2017
352
244
86
Let’s see, same VEGA architecture? Check!
Similar ram bandwidth? Yes!
Fewer CUs at higher clocks? Yes!
Desktop 3000g series processors running at higher clocks than mobile ones already? Yes!

I don’t know why anyone is shocked.

the big difference will be overclocking. I suspect that Renoir on desktop will tolerate high DRAM clocks much better than raven ridge. The iGPU may also tolerate another 10% on the clocks as well. That should be noticeably better than the 3400g.
 

Shivansps

Platinum Member
Sep 11, 2013
2,844
612
136
Let’s see, same VEGA architecture? Check!
Similar ram bandwidth? Yes!
Fewer CUs at higher clocks? Yes!
Desktop 3000g series processors running at higher clocks than mobile ones already? Yes!

I don’t know why anyone is shocked.

the big difference will be overclocking. I suspect that Renoir on desktop will tolerate high DRAM clocks much better than raven ridge. The iGPU may also tolerate another 10% on the clocks as well. That should be noticeably better than the 3400g.
I dont think anybody is shocked, still the results look a little low, the top 3200G/Vega 8 score on FireStrike was archived at 1780mhz and DDR4-3466 with 4650 GS, compared to 4300 on 4700G 2100mhz and DDR4-3200... clear ram bottleneck there, but still.
 

LightningZ71

Senior member
Mar 10, 2017
352
244
86
I dont think anybody is shocked, still the results look a little low, the top 3200G/Vega 8 score on FireStrike was archived at 1780mhz and DDR4-3466 with 4650 GS, compared to 4300 on 4700G 2100mhz and DDR4-3200... clear ram bottleneck there, but still.
Very reasonable question. I think that we've known that VEGA iGPUs are heavily ram bottlenecked, and a roughly 7-8% difference in RAM bandwidth giving a nearly matching 7-8% difference in the final score follows that well.

What I'm hoping for is support for DDR4-4266 with reasonable latencies on current motherboards. I don't think that is too far fetched what with the Chip's support for LPDDR4X-4266 in mobile configurations. Given how ram bandwidth constrained VEGA8 is, if it can maintain 2+ GHz clocks with 4266 ram (greater ram bandwidth will result in greater GPU utilization, increasing heat output), we should see decent improvements in the scores.
 

DrMrLordX

Lifer
Apr 27, 2000
15,753
4,714
136
@LightningZ71

DDR4-4266 is already supported on x570 motherboards. I got DDR4-4400 running once, though the bandwidth numbers were not very good. When you go into async mode, it isn't just latency that suffers.
 
  • Love
Reactions: mopardude87

Hans Gruber

Senior member
Dec 23, 2006
893
236
116
@LightningZ71

DDR4-4266 is already supported on x570 motherboards. I got DDR4-4400 running once, though the bandwidth numbers were not very good. When you go into async mode, it isn't just latency that suffers.
I think what people are talking about is over 4000mhz in coupled mode. That way the latency would not get out of control. The fabric clock with Zen 2 is off when you get over 3733mhz. Supposedly Zen 3 solves a lot of the problems we have seen in Zen 2 with the infinity fabric. So your 4400mhz may be stable with Zen 3.
 

DisEnchantment

Senior member
Mar 3, 2017
524
914
106

1591444885555.png

New super computer award for AMD,
128 Core EPYC Milan :eek:

The 128 Core does not seem to be a typo
1 Billion CPU Cores/Year [ 128 Cores * 1000 CPUs * 24 Hours * 365 Days = 1.12 Billion CPU core hours / year ]

They could be SMT cores. I hope they are SMT cores.
Doubling core count again would imply AMD is still sticking with tiny cores which IMO needs to change. For future processes sure, it would be a great idea.
Unless ...
 
Last edited:

mopardude87

Platinum Member
Oct 22, 2018
2,743
1,061
96
@LightningZ71

DDR4-4266 is already supported on x570 motherboards. I got DDR4-4400 running once, though the bandwidth numbers were not very good. When you go into async mode, it isn't just latency that suffers.
Oh dayum, i am thinking of trying to amp up mine. I got horrible timings as it is on this kit. I honestly got no idea what will benefit more, tighter timings on this kit or sheer speed LOL.
 

Shivansps

Platinum Member
Sep 11, 2013
2,844
612
136
@LightningZ71

DDR4-4266 is already supported on x570 motherboards. I got DDR4-4400 running once, though the bandwidth numbers were not very good. When you go into async mode, it isn't just latency that suffers.
Thats why ive mentioned the possibility of Renoir archiving higher fabric speeds than Matisse, it kinda should considering it is 7nm monolithic, not sure if enoght for 4266 whiout going async, but maybe 4000.
 

LightningZ71

Senior member
Mar 10, 2017
352
244
86
Renoir doesn't couple DRAM speeds to IF speeds like Matisse does. I encourage you to go to your local search engine and look it up. It runs various internal ratios depending on the frequency spread, but it's always uncoupled.

My commenton achievable memory speeds wasn't just directed at x570 boards. I suspect that some AM4 boards are less capable of achieving high memory clocks than others. I also don't know how good the Renoir IMC will be on desktop AM4 sockets. There are a lot of variables at play here.

The only thing that's certain is that Renoir's VEGA will be highly memory bandwidth constrained beyond 2Ghz (and lower) and every additional MHz of RAM bandwidth will be valuable.
 

moinmoin

Golden Member
Jun 1, 2017
1,611
1,508
106

View attachment 22391

New super computer award for AMD,
128 Core EPYC Milan :eek:

The 128 Core does not seem to be a typo
1 Billion CPU Cores/Year [ 128 Cores * 1000 CPUs * 24 Hours * 365 Days = 1.12 Billion CPU core hours / year ]

They could be SMT cores. I hope they are SMT cores.
Doubling core count again would imply AMD is still sticking with tiny cores which IMO needs to change. For future processes sure, it would be a great idea.
Unless ...
Personally wouldn't expect another doubling of cores with Milan, only with Genoa. Maybe they actually mean threads instead cores? If not that's one hell of an accidental leak.
Also Dell of all companies doing a supercomputer with AMD hardware?
 

Hitman928

Platinum Member
Apr 15, 2012
2,508
1,654
136
Personally wouldn't expect another doubling of cores with Milan, only with Genoa. Maybe they actually mean threads instead cores? If not that's one hell of an accidental leak.
Also Dell of all companies doing a supercomputer with AMD hardware?
Yeah, pretty sure it's either threads or they are using dual socket blades and that's where the confusion is coming in.
 
  • Like
Reactions: ksec

DrMrLordX

Lifer
Apr 27, 2000
15,753
4,714
136
I think what people are talking about is over 4000mhz in coupled mode. That way the latency would not get out of control. The fabric clock with Zen 2 is off when you get over 3733mhz.
In those cases, it isn't the motherboard that's the bottleneck.
 

Shivansps

Platinum Member
Sep 11, 2013
2,844
612
136
Renoir doesn't couple DRAM speeds to IF speeds like Matisse does. I encourage you to go to your local search engine and look it up. It runs various internal ratios depending on the frequency spread, but it's always uncoupled.

My commenton achievable memory speeds wasn't just directed at x570 boards. I suspect that some AM4 boards are less capable of achieving high memory clocks than others. I also don't know how good the Renoir IMC will be on desktop AM4 sockets. There are a lot of variables at play here.

The only thing that's certain is that Renoir's VEGA will be highly memory bandwidth constrained beyond 2Ghz (and lower) and every additional MHz of RAM bandwidth will be valuable.
That may be a power saving feature. In the end what matters is having higher fabric speeds than Matisse, if is coupled or not is not that important.
I need to look that up, but im not that much interested in the mobile versions.
 

IntelUser2000

Elite Member
Oct 14, 2003
6,828
1,389
136
Yeah, pretty sure it's either threads or they are using dual socket blades and that's where the confusion is coming in.
Hmm, maybe not.

1,000 128-core AMD Epyc “Milan” processors
peak performance of 5.3 petaflops.
At 3GHz, a 64 core Rome CPU delivers 3072GFlops, or 3TFlops. 1000 Milan CPUs offering 5.3 PFlops gives us three options:

1. 5.3GHz 64 core
2. 128 core 2.6GHz
3. 64 core 2.6GHz with full fledged AVX-512(that is, 2x 512-bit vector units per core)

1 is out of the question. So that leaves us with 128 cores, or double FP performance. Unless AMD is going 5nm, I don't really see them going with that many cores. And even if its 5nm, you won't double perf/watt and they'll use some of the efficiency gains on the wider uarch anyway.

The most logical choice seems to be a 64 core part with Zen 3 supporting 2x AVX512 capable units.

Oh, that was a mistake, they meant 128 cores per node, not per socket.
Or that lol.
 
Last edited:

DrMrLordX

Lifer
Apr 27, 2000
15,753
4,714
136
In the end what matters is having higher fabric speeds than Matisse, if is coupled or not is not that important.
Unless AMD has "fixed" the performance problems that crop up when you're in async mode, having synced IF/RAM is much more important that IF speed.

edit: I want to amend this slightly with some data from my own system.

RAM 1833/IF 1833:
Read: 57994 MB/s
Latency: 65.4ns

RAM 1833/IF 1800 (async):
Read: ~57400 MB/s
Latency: 74.8ns

So clearly, in terms of bandwidth, async alone isn't doing that much to hurt performance (though it stings a bit). Latency is another story.
 
Last edited:

Shivansps

Platinum Member
Sep 11, 2013
2,844
612
136
Unless AMD has "fixed" the performance problems that crop up when you're in async mode, having synced IF/RAM is much more important that IF speed.

edit: I want to amend this slightly with some data from my own system.

RAM 1833/IF 1833:
Read: 57994 MB/s
Latency: 65.4ns

RAM 1833/IF 1800 (async):
Read: ~57400 MB/s
Latency: 74.8ns

So clearly, in terms of bandwidth, async alone isn't doing that much to hurt performance (though it stings a bit). Latency is another story.
For IGP gaming latency is secondary to bandwidth, memory timings that has a large impact on bandwidth are more important than the ones on latency, so the same will apply to coupled/async. But those 600MB/s lost there is in fact significant for an APU, for a CPU only i dont think so. Consideing how well those IGP are performing compared to a RX550 with 128-bit GDDR5 i dont think a CPU core uses much bandwidth while gaming, not sure if this was ever tested, that would also change depending on game and will explain a lot.
 

ASK THE COMMUNITY