This week, AMD formally launched its new Ryzen™ 9 7900X3D and Ryzen 9 7950X3D processors. These CPUs all feature an additional 64MB of vertically mounted L3 cache. This three-dimensional vertical cache – 3D V-Cache™ for short – provides a potent performance boost in gaming and in some content creation workloads.
One unique feature of the Ryzen 9 7900X3D and Ryzen 9 7950X3D processors is their asymmetric chiplet configuration. Both chips contain two Core Chiplet Dies (CCDs), but the two CCDs are configured differently.
One CCD offers an additional 64MB of L3 3D V-Cache (96MB total), while the other has a standard 32MB L3 cache but runs at higher clock speeds. But why build a processor with two different chiplets? Wouldn't it have been simpler to use the same silicon for both?
Let's talk about why AMD went this route, starting with a bit more information on what a CCD is.
A CCD, sometimes also called a "chiplet", is a cluster of eight CPU cores that share access to a common L3 cache. Some AMD CPUs, like the Ryzen 7 7700X and Ryzen 7 7800X3D, have one active CCD per physical processor. Higher-end chips in the Ryzen 9 Series have two active CCDs, typically referred to as CCD0 and CCD1.
Up until now, all AMD Ryzen 9 processors have been configured symmetrically, with the same amount of L3 cache on both chiplets. AMD could have gone this route with the new Ryzen 9 7900X3D and Ryzen 9 7950X3D as well, but a symmetric configuration with 64MB of additional 3D V-Cache on both CCDs wasn't the best way to maximize performance.
3D V-Cache delivers real performance improvements in games and certain multimedia encoding workloads, but not every application benefits from additional cache. Some apps care more about higher clock rates or are designed to scale well across many cores.
In the case of the Ryzen 9 7900X3D and Ryzen 9 7950X3D, the two CCDs present on each chip are tuned differently. CCD0 runs at a modestly lower clock than CCD1 but offers 64MB of 3D V-Cache to boost performance. CCD1 is optimized for clock speed and offers the same 5.7GHz peak turbo frequency as the Ryzen 9 7950X1.
This flexibility is a feature of chiplet designs. Including a CCD optimized for each type of workload allows AMD to target a broad range of applications and games more effectively.
Which Chip Should You Choose?
The Ryzen 9 7900X3D and Ryzen 9 7950X3D are designed for users who want to balance gaming, content creation, and efficiency. Compared to the original Ryzen 9 7950X and Ryzen 9 7900X, the 3D V-Cache-equipped X3D processors offer higher gaming performance and a lower maximum TDP2. Users who don't prioritize gaming as one of their most important workloads may prefer a non-X3D chip. When the Ryzen 7 7800X3D arrives in a few weeks, it will be the eight-core CPU of choice for gamers who don't need extra cores and just want maximum gaming performance.
These three parts, combined with our new 65W chips, expand the AM5 ecosystem. Collectively, they deliver the benefits of AM5 and the Ryzen 7000 Series to a wide range of price points and use cases.
Footnotes:
1 - Max boost for AMD Ryzen processors is the maximum frequency achievable by a single core on the processor running a bursty single-threaded workload. Max boost will vary based on several factors, including, but not limited to: thermal paste; system cooling; motherboard design and BIOS; the latest AMD chipset driver; and the latest OS updates. GD-150.
2 - RPL-043: Testing as of 09 February, 2023, by AMD Performance Labs using the following hardware: AMD AM5 Reference Motherboard with AMD Ryzen 9 7950X3D, G.Skill DDR5-6000 and NZXT X63 cooler, versus AMD AM5 Reference Motherboard with Ryzen 9 7950X processor, G.Skill DDR5-6000, and NZXT X63 cooler. ALL SYSTEMS configured with an open-air test bench, Windows 11, AMD Smart Access Memory technology ON, Virtualization-Based Security (VBS) OFF. Gaming performance calculated across 20 select titles, all at 1080p high settings. System manufacturers may vary configurations, yielding different results.
