Question Understanding Renoir Monolithic 8C/16T CPU

nicalandia

Senior member
Jan 10, 2019
247
150
76
I am intrigued by Renoir monolithic CPU design, I believed it was a single chunk of silicon with 8 zen2 cores talking to each other without the separate IO die, but I was told that is not the case and it's that the IO was just shrunk to 7nm and placed closed together, each CCX need to use the IO to talk to each other. Or Renoir is more like Zen 1 each CCX have their own separate Uncore?
 

lobz

Golden Member
Feb 10, 2017
1,110
971
106
I am intrigued by Renoir monolithic CPU design, I believed it was a single chunk of silicon with 8 zen2 cores talking to each other without the separate IO die, but I was told that is not the case and it's that the IO was just shrunk to 7nm and placed closed together, each CCX need to use the IO to talk to each other. Or Renoir is more like Zen 1 each CCX have their own separate Uncore?
You were told wrong. There's no separate I/O die or separate piece of silicone there. Renoir is a fully monolithic SoC.
 

nicalandia

Senior member
Jan 10, 2019
247
150
76
You were told wrong. There's no separate I/O die or separate piece of silicone there. Renoir is a fully monolithic SoC.
As monolithic as Zen 1 8C/16T? Which is really not monolithic because it's two CCX "glued" together with IF.

So it's 8C/16T Renoir CPU side is still two separate Zen2 CCX clusters talking to each other thru Infinity Fabric? and if so does that count as Monolithic?
 

teejee

Senior member
Jul 4, 2013
291
87
101
So it's 8C/16T Renoir CPU side is still two separate Zen2 CCX clusters talking to each other thru Infinity Fabric? and if so does that count as Monolithic?
Monolithic only means it is one single die. It doesn't say anything more about the architecture.
 

lobz

Golden Member
Feb 10, 2017
1,110
971
106
As monolithic as Zen 1 8C/16T? Which is really not monolithic because it's two CCX "glued" together with IF.

So it's 8C/16T Renoir CPU side is still two separate Zen2 CCX clusters talking to each other thru Infinity Fabric? and if so does that count as Monolithic?
You really changed your original question there... Nevertheless, @Hitman928 answered your further questions as well.
 

eek2121

Senior member
Aug 2, 2005
428
309
136
As far as I am aware Intel 8C/16T cores are not divided separate compute units(yeah I know they use their own type of fabrics in their MCM designs)
You are reading too much into monolithic. A monolithic die simply means one die. Nothing more.

Also, fun fact: all Intel dies have at least 2 separate sets of compute units: the CPU cores and GPU cores. That is also assuming you don't count other parts of the CPU as "compute" or "execution" units.
 

jamescox

Member
Nov 11, 2009
52
62
91
I would be curious to know the internal architectural details. It is probably a similar switch as to what is used in Ryzen 3000 IO die. They probably just stripped out all of the interfaces since they are unnecessary on die. In Ryzen 3000 chips and IO die, everything has to get packetized, serialized, and sent across an external serdes interface. It really is kind of like old style chipset/north bridge, but old north bridges are not operating at something like 50 GB/s. The monolithic die should have slightly lower latency, but it may not be as much lower as you would think at first glance. Data still needs to go through the switch. The off die serdes connections in desktop Ryzen 3000 probably don’t add much latency since they operate at ridiculously high clock rates.
 

ASK THE COMMUNITY