Old rumor post has been more and more accurate as time goes on

1 : Anonymous2021/10/28 06:09 ID: qhgg4i

So to be clear I am not posting this AS a rumor post, but rather a discussion about the idea of random rumor leaks. I find it very interesting how there was this one-off rumor post on another Reddit sub that has since slow had bits and piece of it come to fruition over time. The post in question is here:

/comments/jpmejf/amd_zen_4_cpus/" class="reddit-press-link" target="_blank" rel="noopener">https://www.reddit.com//comments/jpmejf/amd_zen_4_cpus/
How does this sub think of rumors like this after a period of time? How many details in a leak start pointing towards verified information that make it change from unsubstantiated rumors to plausible leak?

Quite a while ago I noticed this thread seemed to be largely ignored and had brought some attention back to it in a new thread on that sub by pointing out some details were looking like they were true. Specifically the poster claimed some wild guesses that in the last few months we have either received confirmation on, or now have much stronger evidence for:

40% IPC uplift over Zen 3 which nobody would believe at first sight. The extremely delayed launch timeframe (at that time). In fact he claimed Q3 2022 before the chip shortages even really began. Did not expect PCI express 5.0 which everyone and their dog thought was a 100% shoo-in at the time. Exceptional cache upgrade that could be what the 3D stacked v-cache ended up being? To be clear this is the limit of my knowledge about PC hardware so I can't interpret too heavily into this part.

I also managed to find an early post about this info here on this sub in google where a couple people very quickly dismissed it as fake and then the thread was soon after deleted. (Old thread located here) One comment caught my attention of someone claiming that 6600 MHz memory not making sense therefore it was automatically fake, yet we have now seen 6600 memory kits from RAM vendors like G Skill in prep for the Alder Lake launch from Intel. (

As a software engineering student, one detail from this post that always stuck with me was his callout of instruction starvation. I do remember learning about that concept as a student and I have just never heard anyone ever call that out from leakers before. I thought it was neat. One last thing sorry for potential typos I'm sleepy af and was thinking about this old AMD post again because of the exciting Alder Lake potential.

2 : Anonymous2021/10/28 09:47 ID: hid1fek

Thanks for post. I didn't see that leak before and it's interesting.

I feel that there's very little evidence for it though. AMD said the PCIe 5.0 will be available on AM5, and most likely that will be available in Zen 4. V-cache has nothing to do with Zen 4 and wasn't mentioned in that post.

That doesn't mean that the post is fake. Nothing there seems unreasonable. However, I don't feel that you have any evidence to back it up.

ID: hid6lb5

Right, my entire point of discussion here is that there's no foundational evidence, but any potential reliability kinda comes from the fact that this post is very old, far older than leaks which did not come for months after this post that started claiming the same information.

Again, things like a 30-40% IPC gain sounded like straight up fanfic. Then what happened? 4 months later major publishers made the same claims. Then they claim that PCIe 5.0 will be absent, while this reddit post claimed that 11 months ago.

AMD said PCI express 5.0 is coming to AM5 sure but that does not mean that it is coming right away. It also seems that people didn't realize just how far memory speeds would be pushed with DDR5 last november. It wasn't until this year companies like Micron starting showing how far they were pushing early DDR5 rather than it taking until end-of-life to get those speeds.

Isn't V-cache mainly just about putting a ton of cache on the CPU die? Isn't that basically what the poster was hinting at? Couldn't the stacked memory essentially be L4 cache?

Also I want to quote something else from that post. Something I didn't catch until literally this moment. To me, this is huge:

We have internal expectations of Intel delivering their own 7nm node in 2022

Intel 7nm in 2022. This to me sounds like they had early expectations of Intel rebranding their fabrication process in the future. Isn't there a saying about the people who know the most about your secrets is your competitor? Sure the timeline is a LITTLE BIT off, but timelines are always adjusted as time goes on. Intel's refined 10nm process is officially Intel 7 now, which is what Alder Lake is coming out as now. Holy shit.

ID: hid8iwe

Then they claim that PCIe 5.0 will be absent

And that turned out to be false.

Couldn't the stacked memory essentially be L4 cache?

No, it's L3 cache.

The point is, the arguments you use to show that the rumour was true are themselves wrong.

ID: hid84mv

I think he actually ment Intel 4 (Which was called 7nm). IIRC Raptor Lake will be made on that process

ID: hif00yy

the most reliable claim is from chip and cheese, who does in-depth testing on CPUs and software and possibly got information leaked to him. 40% would match the engineering sample's overall performance gains, but he was saying IPC gain was more around 29%, with total gains up to 40% from frequency improvements.

That said it was also an early engineering sample (almost two years early) so those results could be based on design goals tested in their labs rather than what they can really ship on 5nm, but at the very least they're shooting for a generational gain instead of a marginal refresh.

ID: hidtfld

Zen 4 will almost certainly utilize V-cache.

ID: hidwtzx

It's possible, but this can go against the rumour, because a large V-cache might mean that L4 isn't needed. (Of course it's also possible that V-cache will be used for the L4, but again, this is unrelated to the rumour, and doesn't confirm it in any way.)

ID: hierzfj

5nm to 5nm tech from TSMC is going to be available in late 2022. So I woundn't count on the first Zen4 iteration to already feature that.

3 : Anonymous2021/10/28 13:52 ID: hidpsc0

People dismissing it because of 6000+ mhz memory seems strange since we have expected AM5 and DDR5 for quite a few years.

4 : Anonymous2021/10/28 11:17 ID: hid8jbt

Lol don't count on it, even documents leaked from hacks are now lookin inaccurate. Those said that the am5 socket and chipset are limited to pcie4.0, we now have amd confirming that am5 supports pcie5.0 (even if the chip might not at launch)

That rumor's sayin that there'd be 4 chiplets with 1 io die but genoa specs already tell us that each ccd is kept at 8 cores and amd execs confirmed that they kept the ccd small for a more modular approach. Amd ain't gonna put 4 x 8 cores onto a client platform

The l3's confirmed to be 32mb for each ccd, there's 0 information on any l4. With vcache why'd amd add l4?

ID: hidlae9

confirming that am5 supports pcie5.0 (even if the chip might not at launch)

I'm not sure why anyone is still holding on to the notion that Raphael won't have PCIe 5.0. Reminds me of 2020 when people kept saying that even though Lisa Su said that Zen 3 will appear in 2020 she probably meant the server chips and not the desktop ones.

ID: hiduoxh

That's just going by the words and being careful

ID: hidp6fx

I wonder if its possible to put two IO dies in there and have half the CCDs access one and the other half use the other.

ID: hiefac4

Amd ain't gonna put 4 x 8 cores onto a client platform

Normally i would agree with you, but the recent MLID leak said the Zen 3 Threadripper CPUs were cancelled. If that leak is true, then it wouldn't surprise me to see a 32-core CPU in the same lineup.

Makes sense to me, given that the increased bandwith supplied by both DDR5 memory and pcie 5.0 chipset could effectively replace the "quad-channel memory and increased chipset lanes" model that HEDT typically used. DDR4 and pcie 4 can be the mainstream platform, while DDR5 and pcie 5 would be the new "HEDT" (along with a higher price tag).

The leak also said that Zen 3 "PRO" threadrippers are still coming, that's were their 64-core and upwards CPUs are going to be used, so that niche would still be available.

5 : Anonymous2021/10/28 11:00 ID: hid70zl

Can somebody remember me what AMD means by CCDs? because interpreting CCDs as the core chiplets we have now that :

The package will be surrounded by 4 CCDs

Doesn't seem right to me, why should the go for 32 cores? If they really manage a 40% IPC improvement + the high frequencies they'll get pushing the TDP to 170W a 24 core should be enought to face Raptor Lake. Also this would leave threadripper margins on the 32 cores CPUs

If those extra CCDs are some kind of accelerators it would be really interesting. IIRC in "5 years of Ryzen" they talked about some kind of neural accelerator for the next generations but probably Zen 4 is too early.

Also, I don't think one of them would be the iGPU rumored for Raphael, adding a couple CUs in the IO die seems smarter to me.

In the end i think it might be real. Moore's Law is Dead sayed that he'll made a Zen 4 video soon because he got some infos, maybe he'll confirm something about the post

PS: That L4 cache seems to refer to 3D vcache but he's wrong about radeon. Infinity Cache il L3, not L4. However, this might just be some internal incomprehesion between CPU and GPU team or maybe it was some prototype idea for IC

ID: hidpm2l

I cannot see how they could cram 32 cores into an AM5 form factor, 24 possibly but that would be pushing it for heat.

Its already stupidly hard to keep a 5950x cool when its running full turbo without using a 360 rad or custom CLC, 24 cores would be even more difficult due to the small form factor of AM5.

ID: hidy9dr

Yeah, they would have to do something crazy like integratig the 3d cache in the IO die and stack the CCDs on top of that.

Also, like with the 5950X the heat generating part would be extremely dense, meaning that even if the consumption is only 170W it would be hard to cool it

6 : Anonymous2021/10/28 18:03 ID: hierik1

Zen 4 FCLK leaked was 2.4GHz or so. The "leaker" said 3.3GHz.

Additionally, V-Cache is not really acting as L4.

7 : Anonymous2021/10/28 20:17 ID: hifbsi6

Rumor accuracy doesn't change over time... it was either true or false or partly true as soon as somebody said it.

Also Zen 4 was thought to be AM5 for ages... and AM5 has been known to be PCIe 5.0 DDR5 also for ages... so much so I wouldn't even call it a rumor.

What is actually changing for the most part is your perception.


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