Intel Optane works with AMD processors

Memory Extension Drive: AMD Epyc (no) has an Optane alternative

A non-volatile memory that supplements conventional DRAM and, for example, permanently holds databases “in-memory”: While Intel's server platforms enable this with fast Optane Persistent Memory, AMD uses the Memory Extension Drive from Western Digital at Epyc - an unequal alternative .

Intel complements system memory with Optane

The creation of new levels in the tried and tested memory hierarchy of computer systems has become a major issue in recent years. With their phase change memory 3D XPoint, Intel and Micron have established a new form of Storage Class Memory (SCM), a non-volatile memory that combines the properties of main memory and mass storage.

While Intel initially served the storage area with 3D XPoint SSDs from the Optane family, with the actual market launch of the Optane Persistent Memory in the DDR4 form factor, only the second side of the coin follows: a non-volatile addition to the volatile DRAM as working memory for servers .

AMD has an alternative to RAM supplement ...

AMD has so far had no alternative for its server processors of the Epyc family, because Optane Memory is only supported by Intel platforms. In order to be able to offer a supplement to the main memory with non-volatile memory, AMD is now cooperating with Western Digital. Both companies announce the compatibility of the so-called Memory Extension Drive with Epyc servers.

The Memory Extension Drive Ultrastar DC ME200 is not based on fast phase change memory and is also not a DDR4 module. Instead, it is an NVMe SSD with NAND flash, which supports the main memory in cache and database applications as a virtual memory pool via software (vSMP from ScaleMP) and enables in-memory computing with huge databases.

... but none of Optane's performance

In terms of performance and write resistance, the Memory Extension Drive cannot keep up with Intel's Optane solution, because conventional NAND flash is much slower and less durable than 3D XPoint, which almost achieves the performance of a RAM disk. In terms of performance, AMD has no alternative with the Memory Extension Drive from Western Digital. Although Western Digital advertises that common cache and database applications still achieve 74 to 94 percent of the performance compared to a pure DRAM system. For "In-memory database machines like SAP HANA, Oracle, IBM and Microsoft as well as scale-out memory-centric architectures like Redis, Memcached, Apache Spark and large databases", Let the Ultrastar drive be a"ideal solution"Says Western Digital.

On the other hand, expanding the main memory with the Memory Extension Drive is cheaper and allows much more storage space for in-memory databases. Because while the Optane modules offer a maximum of 512 GB of storage space and a dual-socket server supports up to 6 TB of this, the NVMe SSD is available with up to 4 TB and thus offers eight times the storage space.

Western Digital gives an example: If a 30 TB database is to be kept in the working memory (in-memory), a server cluster with 30 nodes each with 1 TB DRAM would previously be necessary. With the memory extension drive, the number of nodes can be reduced to eight with 4 TB each. A 1U server can be expanded to up to 24 TB of system memory using the Memory Extension Drive. In contrast to Optane, the solution is not tied to a platform and can also be used with Intel servers.

Western Digital describes how the Memory Extension Drive works in its own blog. The ComputerBase report on the presentation of the Ultrastar DC ME200 also provides further information.

  • Michael Günsch email
    ... has been writing about PC hardware such as graphics cards, monitors and SSDs as well as about research, games and business since 2009.