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

[Vattila]

Except for the details about the improvements in the microarchitecture, we now know pretty well what to expect with Zen 3.

The leaked presentation by AMD Senior Manager Martin Hilgeman shows that EPYC 3 "Milan" will, as promised and expected, reuse the current platform (SP3), and the system architecture and packaging looks to be the same, with the same 9-die chiplet design and the same maximum core and thread-count (no SMT-4, contrary to rumour). The biggest change revealed so far is the enlargement of the compute complex from 4 cores to 8 cores, all sharing a larger L3 cache ("32+ MB", likely to double to 64 MB, I think).

Hilgeman's slides did also show that EPYC 4 "Genoa" is in the definition phase (or was at the time of the presentation in September, at least), and will come with a new platform (SP5), with new memory support (likely DDR5).

What else do you think we will see with Zen 4? PCI-Express 5 support? Increased core-count? 4-way SMT? New packaging (interposer, 2.5D, 3D)? Integrated memory on package (HBM)?

Vote in the poll and share your thoughts!

 

[poke01]

Here lies Intel Xeon. Death by Genoa.

Xeon: 1998 - 2022 RIP

 

[poke01]

I have to say AMD is truly a monster, creating such mighty CPUs and with no big delays is honestly so great. Huge respect for AMD.
They will rule datacentre for a long while.

 

[BorisTheBlade82]

Did you mean this:
View attachment 70765

Thanks, so write is limited at around 32Gbyte/s as expected.

In the Genoa presentation they finally answered the question, why they have 2 GMI/IFoP links per CCD:
They are using both for <=4 CCD SKUs (wide mode) and only one (narrow mode) above.
This gives more RAM/IO bandwidth to lower core count SKUs - which was a weakness before.
They could have done the same at the Desktop in order to fully use the available DDR5 bandwidth. But seems it was not worth it from a cost (IOD area) and power perspective.

 

[Joe NYC]

5800x3d @ 1800:3600 XMP timings

Latency = 78.82ns
View attachment 70733

Dram read bandwidth = 37.89 GB/s
View attachment 70734

7950x single CCD (8cores only) "6200MT/s" 2133 FCLK

Latency = 71.22ns
View attachment 70735

Dram read bandwidth = 67.70 GB/s
View attachment 70736

As a side note, it looks like the 5800x3d gets much of its gaming prowess from around the 100mb datasize..
Most games must use that data size.. (?)

V-cache difference is showing from 65mb upto 262mb
(5800x3d vs my "8core" Zen4 below)

Latency:
View attachment 70737 vs View attachment 70753

Bandwidth:
View attachment 70747 vs View attachment 70752

Nearly double the bandwidth and about 33% lower latency of Zen 4 L3 looks good (vs. 5800x3d). Let's see if Zen 4 3D can maintain it.

 

[alexruiz]

Those new EPYCs make the Ryzens 7000 look like toys!
They are nothing short of impressive

 

[Markfw]

Those new EPYCs make the Ryzens 7000 look like toys!
They are nothing short of impressive

Well, not exactly. The 9654 is 6 7950x's in one package, same hardware, just 6 times as much of it.

I am very impressed with my 7950x's, and this comes as no surprise that 6 times this hardware would be even more impressive.

 

[moinmoin]

If nothing else this Genoa presentation once more shows that AMD is still all about server CPUs first. Looking forward to Bergamo and Genoa-X now.

AMD has to break loose any remaining resistance to the idea of buying non-Intel server hardware. There are still diehards that want the next Intel solution. AMD's marketing has to keep hammering the point home to get through to those people. They have the hot hand, and it's time for them to play it aggressively. "Build it and they will come" alone won't be enough.

I don't disagree. Just not sure this event was the place to do that, in this way. The constant "see how many older Intel parts this could replace and how much x that saves" during the over an hour long stream was very tiring. AMD did show its own generational improvement which was impressive as well, that could have gotten more focus.

 

[Timorous]

If nothing else this Genoa presentation once more shows that AMD is still all about server CPUs first. Looking forward to Bergamo and Genoa-X now.


I don't disagree. Just not sure this event was the place to do that, in this way. The constant "see how many older Intel parts this could replace and how much x that saves" during the over an hour long stream was very tiring. AMD did show its own generational improvement which was impressive as well, that could have gotten more focus.

Why? Will customers who purchased Milan servers in the last couple of years be looking at upgrades? Probably not. The customers looking for upgrades will be running 5 year old Intel system give or take so showing how much they can consolidate and reduce ongoing costs is pretty important.

 

[moinmoin]

Why? Will customers who purchased Milan servers in the last couple of years be looking at upgrades? Probably not. The customers looking for upgrades will be running 5 year old Intel system give or take so showing how much they can consolidate and reduce ongoing costs is pretty important.

Sure, but they went on and on for over an hour with essentially that sole topic. I think it would be more effective in a more succinct way.

 

[Abwx]

Seems that Intel managed to keep roughly 80% of the server market despite a more than outdated plateform, at some point competitivness seems to struggle against urban legends based mindshare...

AMD-CPU-Marktanteil: Server hui, Desktop und Notebook pfui

Während AMD mit Epyc weiter auf Intel aufholt, ist der Marktanteil im Desktop und Notebook regelrecht kollabiert.

www.computerbase.de

 

[bsp2020]

Remember, there are no bad processors (assuming theybpass validation), only bad prices...

I don't think this is necessarily true in this case unless Intel price its offerings at a negative price. Operating costs for Intel servers may be too high for them to be competitive at any price that Intel wants to charge.

With that said, Intel still has a huge manufacturing capacity. So, if a large customer wants to replace their aging servers, they may still have to buy from Intel only because they can't wait for AMD to manufacture enough of the new server chips. Then again, AMD said that they won't be capacity limited. I'm looking forward to seeing how fast they can ramp up their production capacity, now that other semiconductor companies are cutting their orders, freeing up manufacturing capacities.

"The more you buy, the more you'll save" applies to AMD servers (https://www.semianalysis.com/p/2023-datacenter-outlook-amd-and-intel) and it would be fullish for big data center operators to hang onto their aging server much longer unless they can't get new AMD servers to replace their current servers. If anything, Semianalysis's analysis seems too conservative to me.

 

[Roger Wilco]

How badly is AMD going to be restricted by fab capacity? It seems like everyone is going to want these amazing chips.

 

[DrMrLordX]

The constant "see how many older Intel parts this could replace and how much x that saves" during the over an hour long stream was very tiring.

Perhaps the vendors with good Intel relations weren't watching that presentation. And yes sitting through an hour of that would be tiresome for someone who is more interested in the technology itself. But, it can serve as a template for presentations elsewhere.

How badly is AMD going to be restricted by fab capacity? It seems like everyone is going to want these amazing chips.

Supposedly, supply won't be as big a problem as it was for Milan.

 

[igor_kavinski]

How badly is AMD going to be restricted by fab capacity? It seems like everyone is going to want these amazing chips.

Intel should cancel SPR and start fabbing Genoa in their fabs. At least, that way they can save on further development costs and get a piece of the Genoa pie.

 

[DrMrLordX]

Seems that Intel managed to keep roughly 80% of the server market despite a more than outdated plateform, at some point competitivness seems to struggle against urban legends based mindshare...

Sorry I didn't notice this comment earlier. It's kind of sad that Intel is maintaining that market share, but that's the market share that AMD has to bust loose, and their main competition in this effort isn't IceLake-SP or Sapphire Rapids, it's Cascade Lake-SP. These are the shops that just keep scaling out with Cascade Lake since Intel keeps lowering prices and vendors keep pushing Intel solutions so hard.

 

[fkoehler]

And I wouldn't be surprised if some people end up getting fired 1-2nd quarter next year when businesses get hit with a 20-30% electricity increase in the US. If they haven't seen their electrical cost go up, they're either not looking or it hasn't filtered to them yet. Not as bad as EU, however its coming.

Some IT Dir or VP is going to get asked why they haven't replaced Intel at x-watts with AMD at x-watts * 0.6 or some such. Facilities or Operations will get to present the current costs, and defer to IT....

 

[igor_kavinski]

Zen 4 gets slightly faster with AMD's optimized compiler: https://www.phoronix.com/review/amd-aocc-4

Additionally, I personally continue to be a bit perplexed why AMD waits until the later EPYC launch before posting AOCC 4.0 rather than striking initially when the Ryzen 7000 series first debuted.

Heck why not ship it earlier as AOCC "beta" for Ryzen testing? I imagine this too comes down to engineering resources and needing all the time they can get to work out the compiler optimizations.

Yes, AMD. Why are you so tardy? GIve your software people more resources.

 

[yuri69]

Yes, AMD. Why are you so tardy? GIve your software people more resources.

AMD has been treating the SW side of their business an afterthought for years. It's sad.

 

[moinmoin]

AMD has been treating the SW side of their business an afterthought for years. It's sad.

May be changing now that Xilinx people are going to take over the handling of much of the software side.

 

[Thibsie]

It's a long shot but you could write to AMD to donate a Genoa server to you for the noble pursuit of science and medicine. Just show them photos of the servers you already have. I think they would be interested in publicity like that.

Yeah but where to write to ?
Marketing I guess ?

 

[In2Photos]

54 game comparison between the 7600X and 13600K.

7600X holds the slight advantage, even with faster memory for Intel and does it using less power.

 

[igor_kavinski]

Yeah but where to write to ?
Marketing I guess ?

I think this one: https://explore.amd.com/server-request/request

 

[Thibsie]

54 game comparison between the 7600X and 13600K.

7600X holds the slight advantage, even with faster memory for Intel and does it using less power.

I didn't expect that conclusion to be honest ...

 

[Doug S]

And I wouldn't be surprised if some people end up getting fired 1-2nd quarter next year when businesses get hit with a 20-30% electricity increase in the US. If they haven't seen their electrical cost go up, they're either not looking or it hasn't filtered to them yet. Not as bad as EU, however its coming.

Some IT Dir or VP is going to get asked why they haven't replaced Intel at x-watts with AMD at x-watts * 0.6 or some such. Facilities or Operations will get to present the current costs, and defer to IT....

Not gonna happen, that's not how things are done in big corporations in my (rather substantial) experience. Capital spending for datacenter grade servers is budgeted yearly and typically part of a longer term multi year plan. They know well in advance which servers they will be replacing as they reach the end of their lifecycle and/or are fully depreciated, and know how much they have budgeted to spend on new ones. They can't just decide to replace servers early because of temporary changes in energy prices, and qualification of new platforms typically takes months so they aren't even close to considering Zen 4 when it has been out for what a week now (though many will have had test systems for a few months already)

I'm sure you've heard the old saw "nobody gets fired for buying IBM"...the reason that saying exists is because it was completely true. The same is true for Intel, nobody is getting fired because they bought Intel servers instead of AMD, even if the AMD servers could have saved on energy cost. These are not decisions a single individual is making in any company of decent size. Intel's reputation carries a lot of weight, and it takes a long time for that reputation to be overcome by the reality on the ground.

If the energy cost increase is seen as substantial the result will be that "performance per watt" is given greater weight in their next evaluation cycle.

The long term trend is increasing energy use - some new datacenters are being built to support 20-30 kw per rack, which is more than double what they were doing a decade ago. What matters to them isn't the efficiency of an individual CPU socket, but what server designs OEMs on your approved supplier list are offering as far as how much computing power they can get per rack and still fit into the per rack power budget. There are a lot more options with Intel CPUs than AMD, that's just the reality because of history and the above reputational issues. That takes years to change.

 

[DrMrLordX]

Not gonna happen, that's not how things are done in big corporations in my (rather substantial) experience. Capital spending for datacenter grade servers is budgeted yearly and typically part of a longer term multi year plan. They know well in advance which servers they will be replacing as they reach the end of their lifecycle and/or are fully depreciated, and know how much they have budgeted to spend on new ones. They can't just decide to replace servers early because of temporary changes in energy prices, and qualification of new platforms typically takes months so they aren't even close to considering Zen 4 when it has been out for what a week now (though many will have had test systems for a few months already)

I'm sure you've heard the old saw "nobody gets fired for buying IBM"...the reason that saying exists is because it was completely true. The same is true for Intel, nobody is getting fired because they bought Intel servers instead of AMD, even if the AMD servers could have saved on energy cost. These are not decisions a single individual is making in any company of decent size. Intel's reputation carries a lot of weight, and it takes a long time for that reputation to be overcome by the reality on the ground.

If the energy cost increase is seen as substantial the result will be that "performance per watt" is given greater weight in their next evaluation cycle.

The long term trend is increasing energy use - some new datacenters are being built to support 20-30 kw per rack, which is more than double what they were doing a decade ago. What matters to them isn't the efficiency of an individual CPU socket, but what server designs OEMs on your approved supplier list are offering as far as how much computing power they can get per rack and still fit into the per rack power budget. There are a lot more options with Intel CPUs than AMD, that's just the reality because of history and the above reputational issues. That takes years to change.

TCO still matters. A lot. Nobody's gonna get fired for still carrying a mix of Cascade Lake-SP and IceLake-SP (in lieu of Milan) through 2022, but if they turn their noses up at Genoa vs. maybe having access to Sapphire Rapids next year (or getting on a waiting list) then that's when some careers might be in danger.

That approved supplier list is going to shake up real soon, if it hasn't already.