Even though AMD's AM5 platform is designed to support all features of DDR5 memory modules, including CUDIMMs, the company's existing Ryzen 7000 cannot work with CUDIMMs at all, whereas Ryzen 8000, and Ryzen 9000-series CPUs do not fully support such modules. Nonetheless, AMD's AMD's AM5 infrastructure has everything to support clock unbuffered memory modules, according to Sourabh Dhir, product management lead for gaming and workstations, who spoke to Digital Trends.
As memory technology evolves, innovations include not only memory chips with a higher data transfer rate but also new DIMM technologies, such as CUDIMMs. In fact, JEDEC's standards presume that all memory modules featuring memory speeds of 6400 MT/s and higher are CUDIMMs (i.e., have a clock driver onboard to ensure cleaner signaling and stability at high transfer rates).
According to AMD, CUDIMM support does not require a platform overhaul: AM5 is already equipped with everything needed to support all kinds of DDR5 enhancements. However, it may take AMD another generation of CPUs to fully support CUDIMMs, as Sourabh Dhir did not explicitly say that AMD's existing or upcoming processors will officially support CUDIMMs at some point.
For now, Ryzen 7000-series processors are completely incompatible with CUDIMM memory modules: if installed, the system will fail to boot. By contrast, Ryzen 8000 and 9000 series CPUs can technically work with CUDIMMs, but only in a limited fallback configuration known as 'bypass mode', which ignores the clock driver chip on the module and, therefore, offers no advantage. This means that the system will start in DDR5-3200 mode and will require manual adjustment of the memory transfer rate, and therefore, there will be no performance guarantees.
It is noteworthy that MSI confirmed that AMD's Ryzen 8000 and 9000 series processors will support CUDIMM memory modules on X870 and X870E motherboards. MSI's overclocker Toppc explained that MSI's latest X870 mainboards feature enhanced signaling capabilities, which improve compatibility with high-frequency memory modules. While Ryzen 8000 and 9000 CPUs could operate with CUDIMMs, the full extent of supported memory speeds is still unannounced, and it is unclear whether AMD's implementation will match the performance levels seen on Intel's Arrow Lake-S, which already supports speeds of 9,200 MT/s and higher.
Achieving transfer rates around 10,000 MT/s still relies on heavily optimized setups with cherry-picked memory chips and increased voltages, which limits near-term mainstream use. CUDIMM modules are designed for officially rated speeds starting at 6,400 MT/s, but most high-end CUDIMM kits are intended for Intel's platform.
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