Just a few hours prior to AMD's CES 2022 keynote, we have received an interesting image of what is rumored to be the chiplet layout of the next-gen Zen 4 cores powering the Ryzen 7000 'Raphael' Desktop CPUs.
AMD Ryzen 7000 'Raphael' CPUs To Feature A Mix of 5nm Zen 4 'Priority' & 'Low TDP' Cores: Up To 16 Cores Per Die With Vertically Stacked L3 Cache
According to the rumored chiplet layout, it looks like AMD will indeed be offering a higher core count in the next iteration of Zen. The 5nm Zen 4 core will power AMD's next-gen Ryzen 7000 'Raphael', Ryzen 7000 'Phoenix', and EPYC 7004 'Genoa' CPUs. This chiplet architecture is specific to the Ryzen Desktop family codenamed Raphael which will launch on the AM5 platform later this year and we are expecting AMD to unveil some details at their CES keynote as they did with the EPYC lineup, unveiling not just the V-Cache 'Milan-X' parts but also Genoa and Bergamo based on the Zen 4 architecture.
So getting right into the details, the rumored chiplet layout suggests that AMD will feature 16 Zen 4 cores on their Raphael chiplets but 8 of those cores will be 'Priority' cores and run at full TDP mode while the rest of the 8 Zen 4 cores will be Low-TDP optimized cores and operate at a combined TDP of 30W. Do remember that Zen 4 Ryzen CPUs are expected to feature up to 170W TDPs. Each Zen 4 'LTDP' and 'Priority' core will feature a shared 1 MB L2 cache but it looks like the V-Cache has gone completely off-die and will instead be vertically stacked with each stack feature 64 MB of L3 cache. If AMD were to use two Zen 4 dies on the Ryzen 7000 CPUs, this would give us 128 MB of L3 cache.
It is also mentioned that the new architectural layout wouldn't require any scheduling updates in software as was the case with Intel's Alder Lake CPUs which utilized a brand new hybrid approach. These backup 'LTDP' cores would only be utilized once the main cores reach 100% utilization and look like an efficient way to make things work instead of just full fat 16 Zen 4 cores running at a higher TDP.
It is also said that the V-Cache stacks will reside on top of the backup cores and the first iteration of this design would only be limited to L3 sharing across the priority cores. The rumors also allege that all 32 core AMD Ryzen 7000 'Raphael' CPUs will feature a 170W TDP and as for the performance, a single 8 'LTDP' Zen 4 core stack with 30W TDP will offer faster performance than the AMD Ryzen 7 5800X (105W TDP).
Here's Everything We Know About AMD's Raphael Ryzen 'Zen 4' Desktop CPUs
The next-generation Zen 4 based Ryzen Desktop CPUs will be codenamed Raphael and will replace the Zen 3 based Ryzen 5000 Desktop CPUs that are codenamed, Vermeer. From the information we currently have, Raphael CPUs will be based on the 5nm Zen 4 core architecture & will feature 6nm I/O dies in a chiplet design. AMD has hinted at upping the core counts of its next-gen mainstream desktop CPUs so we can expect a slight bump from the current max of 16 cores and 32 threads.
The brand new Zen 4 architecture is rumored to deliver up to 25% IPC gain over Zen 3 and hit clock speeds of around 5 GHz. AMD's upcoming Ryzen 3D V-Cache chips based on the Zen 3 architecture will be featuring stacked chiplets so that design is expected to be carried over to AMD's Zen 4 line of chips too.
AMD Ryzen 'Zen 4' Desktop CPU Expected Features:
- Brand New Zen 4 CPU Cores (IPC / Architectural Improvements)
- Brand New TSMC 5nm process node with 6nm IOD
- Support on AM5 Platform With LGA1718 Socket
- Dual-Channel DDR5 Memory Support
- 28 PCIe Lanes (CPU Exclusive)
- 105-120W TDPs (Upper Bound Range ~170W)
As for the platform itself, the AM5 motherboards will feature the LGA1718 socket which is going to last quite some time. The platform will feature DDR5-5200 memory, 28 PCIe lanes, more NVMe 4.0 & USB 3.2 I/O, and may also ship with native USB 4.0 support. There will be at least two 600-series chipsets for AM5 initially, the X670 flagship and B650 mainstream. The X670 chipset motherboards are expected to feature both PCIe Gen 5 and DDR5 memory support but due to an increase in size, it is reported that ITX boards will only feature B650 chipsets.
The Raphael Ryzen Desktop CPUs are also expected to feature RDNA 2 onboard graphics which means that just like Intel's mainstream desktop lineup, AMD's mainstream lineup will also feature iGPU graphics support. In regards to how many GPU cores there will be on the new chips, rumors say anywhere from 2-4 (128-256 cores). This will be lesser than the RDNA 2 CU count featured on the soon-to-be-released Ryzen 6000 APUs 'Rembrandt' but enough to keep Intel's Iris Xe iGPUs at bay.
AMD Mainstream Desktop CPU Generations Comparison:
|AMD CPU Family||Codename||Processor Process||Processors Cores/Threads (Max)||TDPs (Max)||Platform||Platform Chipset||Memory Support||PCIe Support||Launch|
|Ryzen 1000||Summit Ridge||14nm (Zen 1)||8/16||95W||AM4||300-Series||DDR4-2677||Gen 3.0||2017|
|Ryzen 2000||Pinnacle Ridge||12nm (Zen +)||8/16||105W||AM4||400-Series||DDR4-2933||Gen 3.0||2018|
|Ryzen 3000||Matisse||7nm (Zen 2)||16/32||105W||AM4||500-Series||DDR4-3200||Gen 4.0||2019|
|Ryzen 5000||Vermeer||7nm (Zen 3)||16/32||105W||AM4||500-Series||DDR4-3200||Gen 4.0||2020|
|Ryzen 5000 3D||Warhol?||7nm (Zen 3D)||8/16||105W||AM4||500-Series||DDR4-3200||Gen 4.0||2022|
|Ryzen 7000||Raphael||5nm (Zen 4)||16/32||170W||AM5||600-Series||DDR5-5200||Gen 5.0||2022|
|Ryzen 7000 3D||Raphael||5nm (Zen 4)||16/32?||105-170W||AM5||600-Series||DDR5-5200/5600?||Gen 5.0||2023|
|Ryzen 8000||Granite Ridge||3nm (Zen 5)?||TBA||TBA||AM5||700-Series?||DDR5-5600+||Gen 5.0||2024-2025?|