NV-DIMM memory modules have the particularity of having non-volatile RAM or NAND Flash inside them, among them the NVDIMM-P stands out, which is based on placing RAM and NAND Flash memory in a single DIMM module, sharing with it the memory bus. Well, AMD will adopt NVDIMM-P memory in future CPUs and APUs. We explain how they will implement it on their hardware.
One of the future improvements that we are going to see both in CPU, GPU and APU is the flash controller integration within the processor as it happened in its day with the RAM memory controller. This in combination with the Compute Express Link or CXL interface, a variant of PCI Express 5.0 onwards, will enable joint communication with both the NAND Flash memory and the system RAM. So in the future we will have memory modules that will integrate memory and storage in a single module.
It is known that we will have NVDIMM modules that combine the DDR5 memory with NAND FLASH memory in a single DIMM. Communication with the processor could be done through a PCIe 5.0 interface. Let’s not forget that Samsung recently introduced a DDR5 memory expansion for one port PCIe with CXL interface. Could DDR modules disappear in favor of PCIe interfaces? Well, AMD has thought about that possibility for the future.
AMD will implement NVDIMM-P interfaces in its future processors
The source of this news is nothing more than AMD itself, specifically a patent entitled ERROR REPORTING FOR NON-VOLATILE MEMORY MODULES where it talks about the implementation of an NVDIMM-P memory interface for the processor and all the changes that have to be made to do so.
In the description of said patent we can read the following:
Computer systems commonly use high-density random access memory (DRAM) chips as main memory. Many of the DRAM chips sold today are compatible with various of the DDR standards that are promulgated by the Joint Electron Devices Engineering Council (JEDEC). DDR memory controllers are used to manage the interface between different agents (accessing these memories) and DDR DRAMs in accordance with published DDR standards.
A non-volatile dual-inline memory module with persistent storage (“NVDIMM-P”) is a type of storage memory that is used instead of standard DDR DIMMs, but includes persistent memory. However, these memories contain different types of error conditions that differ from DDR error conditions. Additionally, the error conditions associated with the NVDIMM-P have different error effects on the operating system running memory-using processes than the error conditions associated with DDR DIMMs.
The patent therefore confirms that AMD has developed a way to use this type of memory modules in your future processors. At the moment we do not know in which generation it will be released. But if we use logic it is clear that a future AMD EPYC 7004 based on the Zen 4 architecture could be a good candidate for the use of this type of memory.