64 core EPYC Rome （Zen2）Architecture Overview？

[lopri]

Looks like the original leak was not totally baseless.

 

[nicalandia]

Looks like the original leak was not totally baseless.

The OP perhaps but the Thread Starter also believed that AMD would have not used 3 chiplets for Ryzen 3000

Think about it: if there are 8 CPU dies, then each one must be 8C/16T with 1 DDR4 memory channel. Such a die is unsuitable for Ryzen. You could use 2 CPU dies + 1 I/O die to make a 16C/32T + 2ch DDR4 MCM package for Ryzen desktop but I don't think it makes sense. Besides, AM4 is a small PGA package, I doubt you can fit a 3-die MCM on it.

 

[moinmoin]

These old threads are fun to reread. Glad I just called BS but didn't say which part.

 

[moinmoin]

Not sure how many people here care about SEV, Secure Encrypted Virtualization. (Personally I think it's a killer feature which I agree with Norrod should be considered standard soon.)

Anyway Forrest Norrod stated the following aside in an interview:
"The virtual machine is encrypted. So the virtual machine or container or even a process—actually the way that we've implemented it you can make it any one of those three—and it's independent. It's managed by a separate key manager in our security processor. So the systems administrator for the server does not control that key. The user of that VM running their workloads on Amazon [Web Services] can control that key, so all of their VMs work as normal, work full performance, there's no performance impact, but even if Amazon wanted to, they couldn't look into that virtual machine."

I didn't know this essentially works on a process level. This is great as this should allow to encrypt/isolate any process even without using VMs or containers.

Another neat tidbit:
SEV originates from the semi custom business work on Xbox One and Playstation 4.
https://www.crn.com/news/components...on-work-led-to-a-big-security-feature-in-epyc

 

[itsmydamnation]

these new slides are totally worth looking at

【福田昭のセミコン業界最前線】 AMDがISSCCで発表したZen2プロセッサのCPUコアとチップレットの技術

AMDは、最新世代のマイクロプロセッサ「Zen2」のCPUコア技術とチップレット技術を、半導体回路技術の国際学会「ISSCC 2020」で2020年2月17日(米国太平洋時間)に発表した。発表は2件の講演にわかれており、まずCPUコア技術(講演番号2.1)を説明し、続いてチップレット技術(講演番号2.2)を説明するという流れだった。

pc.watch.impress.co.jp

https://pc.watch.impress.co.jp/img/pcw/docs/1236/258/html/photo003_o.jpg.html

see if you just made that bit thats like 1/25th of the core 6 units instead of 4 you would get 50% more IPC!!!

The cost for chiplet vs monolithic also confirms what we all knew 🙂