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  • Writer's pictureFred

AMD EPYC SOC 6096 Nirvana

Updated: Nov 7, 2022

The new EPYC Genoa Chips will be ZEN 4, 5nm next-gen Processors that use the new massive AM5 LGA 6096 SP5 Socket. They are er...rather large!

One of the newer Gen EPYC'S, the AMD EPYC 9664 CPU will have up to 96 cores and 192 threads of CPU power, 12-channel DDR5-5200 memory support, 128 PCIe 5.0 lanes per CPU, and a range from 400W to 700W of TDP @ 3.9 GHz.

AMD are using 12 CCDs in this beast's 96-core, 192-thread CPU Engine with each of the CCDs featuring 8 CPU cores based on the new Zen 4 EPYC architecture.

As for the cache, the AMD EPYC 9664 is armed with 32MB of L3 cache per CCD, which is also shared across all of its Zen 4 cores within the CCD.

AMD built 384MB of L3 cache + 96MB of L2 cache which combined add up to a monster 480MB of pooled cache on this latest EPYC 9664 chip.

The new AMD EPYC "Genoa-X" processor they leaked info about recently is based on the new Zen 4 architecture, packing the new AMD 3D V-Cache technology... driving up to over 1GB of L3 cache which is pure cache insanity.

Even the kick ass EPYC "Milan-X" CPU has 768MB of L3 cache and that was great, but 1GB+ is a massive step up for AMD.

Now in terms of desktop computing for home users the new Ryzen 7000 series is being manufactured right now with the 7900X and 7950X chips of keen interest to me and my ilk.

I also heard from a little birdie that the Genoa Zen 4 goodies will deliver Ryzen 9900X and 9590X fare as well, of which there are prototypes already.

I cannot imagine the AM5 Socket size for those motherboards!

Once again things in chip design are trans-mutating into a different dimension as we get nearer to Zen 5 which will be a brand new from the ground up Micro-architecture that is completely new.

AMD’s CPU core roadmap isn’t broken into specific years, instead giving us a range from 2019 to the end of 2024. The Zen 4 chips will ship by the end of this year (2022), so we can assume the Zen 4 section of the above roadmap begins in 2022.

Moving forward, AMD’s cores will come in three flavors: The standard cores that are listed merely as ‘Zen 4,’ the 3D V-Cache equipped cores, and ‘Zen 4c’ density-optimized cores. Zen 4 will come in the already-announced 5nm variants, but we’ll also see 4nm cores.

These 4nm Zen 4 cores could serve as a broad refresh generation for all chips, or AMD could choose to only use 4nm for certain classes of chips as we see with the 7nm Zen 3 Ryzen desktop PC models and the 6nm Zen 3 Ryzen Mobile processors.

The same rules apply to the Zen 5 cores: AMD has split Zen 5 cores into standard, 3D V-Cache, and ‘ Zen 5c’ variants. The Zen 5 era will debut with a 4nm process, presumably from TSMC, and 3nm variants will also be on offer, though the timing of their arrival isn’t clear.

AMD’s CPU roadmap slide ends in 2024, so these cores will debut in 2024.

AMD’s Zen 3 cores equipped with 3D V-Cache are already on the market with the Ryzen 7 5800X3D, our current best CPU for gaming, and the Milan-X processors. These chips have a chunk of SRAM melded on top of their compute dies via an innovative hybrid bonding process.

AMD says 3D V-Cache chips will become a fixture across its chip families in certain strategic products, but hasn’t committed to any specific number of SKUs for any given family.

The Zen 4c and Zen 5c cores are conceptually similar to the efficiency cores (e-cores) that we see with other types of chip architectures in both Arm and x86 flavors.

AMD will use these cores to craft ultra-dense server chips that are optimized for heavily-threaded cloud workloads.

AMD also disclosed today that the ‘c’ cores support threading, so the upcoming EPYC Bergamo chips, which feature the Zen 4c cores, will come with an astounding 128 cores and 256 threads.

These 'c' cores are smaller than the standard Zen 4 core that will debut in Genoa, with certain unneeded functionality removed to improve compute density.

The chips have a density-optimized cache hierarchy to increase core counts, thus addressing cloud workloads that need higher thread density.

This could mean that the chips have a smaller cache(s), or perhaps a cache level has been removed, but AMD hasn't shared details. The Zen 'c' cores support the full Zen 4 ISA — unlike what Intel does with Alder Lake, AMD won't disable some features like AVX.

AMD announced that its Zen 5 architecture will come to market in 2024.

We can expect a much more significant generational improvement from Zen 5 than we see with Zen 4 due to a new grounds-up redesign of the microarchitecture.

As you would expect, AMD targets improved performance and efficiency for the design.

AMD says it accomplishes those goals by leveraging a re-pipelined front end and increased issue width.

AMD also points to integrated AI and machine learning optimizations, which could come as hardware support for newer numerical formats or matrix multiply units.

AMD’s early adoption of a chiplet-based architecture was made possible by the Infinity Architecture.

This interconnect ties together chiplets, memory and I/O dies, and AMD even uses it to connect accelerators, like its GPUs, for data center applications.

The overarching Infinity Architecture is a key component of the company’s chipmaking tool chest, allowing it to tie together chiplets and other components.

Now AMD plans to widen the umbrella and add extensions that support the Xilinx IP it recently acquired.

AMD will also support IP from third-party vendors, thus giving it access to a wider range of additives.

CXL is an industry-standard cache-coherent interconnect that provides an interface between CPUs and other devices, like GPUs, FPGAs, and memory devices.

AMD joined the broadly-supported CXL consortium in 2019, and will now support CXL 2.0-based memory with its 4th-Gen Infinity Architecture.

That means we’ll see devices like Samsung’s 512GB CXL Memory Expander supported by AMD processors, probably specifically for the data center.

AMD also plans to support CXL 3.0.

AMD also joined the Universal Chiplet Interconnect Express (UCIe) consortium this year.

UCIe aims to standardize die-to-die interconnects between chiplets with an open-source design, thus reducing costs and fostering a broader ecosystem of validated chiplets.

AMD reiterated its commitment to the UCIe standard for its future Infinity Architecture iterations.

All these tools give AMD the lead in chiplet-based products, with more than 50 products on the market already.

The addition of industry-standard interconnects will certainly broaden the company’s scope, particularly when it chooses to integrate chiplets from outside vendors.

As expected, these early details are rather sparse, so stay tuned for updates!


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