Intel Optane Persistent Memory 200 Series

Intel Optane Persistent Memory represents a new class of memory and storage technology explicitly architected for data center usage. It offers three main benefits:

• Significantly lower latency than fetching data from system storage
• High capacities
• Affordable cost

Intel Optane Persistent Memory 200 Series is the second generation of a high performing persistent memory tier that is optimized for third-generation Intel Xeon Scalable processors that helps turn data into actionable insights.

Using Lenovo ThinkSystem servers running applications that are tuned for Intel Optane Persistent Memory will result in lower data latency compared to solid-state drive technology. When data is stored closer to the processor on nonvolatile media, applications can see significant overall improvement in performance. 

The 200 Series module is shown in the following figure, with its blue full-DIMM heat spreader.

Figure 1. Intel Optane Persistent Memory 200 Series

Intel Optane Persistent Memory (PMem) modules (also known as DCPMM) have the form factor of a DDR4 DIMM, but the persistence and capacity of data storage of a solid-state drive. This means the PMem modules have performance characteristics similar to that of TruDDR4 DIMMs, the storage capacity of an SSD, and the ability to stay active after a power cycle or reboot of the server. These features open up a new way of performing data I/O to application developers and new levels of server performance to customers.

The following table lists the ordering information for the persistent memory options.

Intel Optane Persistent Memory 200 Series work with third-generation Intel Xeon Scalable processors and operate in App Direct mode or Memory Mode:

• When used with 4-socket capable "Cooper Lake" processors, PMem modules only operate in App Direct mode
• When used with 2-socket capable "Ice Lake" processors, PMem modules can be configured to operate in either App Direct mode or Memory Mode

App Direct mode

In App Direct mode, PMem provides all persistence features to the operating system and applications that support them. The operating system presents both TruDDR4 DIMMs and PMem modules to the applications, as system memory and persistent storage respectively.

Depending on the configuration in UEFI and the operating system, the PMem modules appear as one of two types of namespaces:

• Direct access (DAX): byte-addressable storage accessible via an API. The applications must be PMem-aware and use the published APIs to implement the PMem features.
• Block storage: the persistent memory is presented to applications is seen as a block storage device, similar to an SSD. The operating system needs to be PMem module-aware, however the applications do not.

In App Direct mode, the persistent memory can be configured in one of two ways:

• Interleaved, where all PMem modules are seen as one single monolithic space per processor. This is similar in concept to RAID-0 in storage.
• Non-interleaved, where each PMem module is seen as a separate space. This is similar in concept to JBOD in storage.

Memory mode

In Memory mode, the PMem modules act as large capacity DDR4 memory modules. In such a configuration, the memory that the operating system recognizes is the PMem modules; the installed TruDDR4 DIMMs are hidden from the operating system and act as a caching layer for the PMem modules. In this mode, the persistence feature of the PMem modules is disabled. This mode does not require the application to be PMem module-aware.

For configure-to-order (CTO) configurations, the feature code listed in the following table specifies you want PMem to operate in Memory mode.

Intel Optane Persistent Memory provides benefits in the following application types:

• Larger memory footprint: For applications with performance characteristics that place greater emphasis on memory capacity over memory bandwidth or memory latency, the use of PMem modules can mean a significant increase in overall system performance compared to the use of TruDDR4 DIMMs. 
  • Cloud and Infrastructure-as-a-service (IaaS) applications
  • More virtual machines and cloud containers per server
  • Larger memory allocation to each VM
• In-memory databases: With PMem modules, database applications have store much larger databases in persistent memory rather than on disk, and database performance will be improved significantly. For existing applications that use system RAM for in-memory databases, the use of persistent memory will mean no delays at boot time having to copy the databases from disk into memory.
• Storage caching layers: TruDDR4 DIMMs can be used for the fastest memory access - best throughput and lowest latency, and PMem modules can be used for the caching layer that offers memory-like performance with the persistence of SSD storage.
• NFV infrastructure: Network Function Virtualization (NFV) can make use of increased memory capacity and performance with the addition of PMem modules.
  • High capacity non-volatile cache for enterprise and cloud storage
  • High capacity local cache for network storage App Direct direct-attach storage

Intel Optane PMem Modules have the following specifications:

• PMem modules are installed in standard memory slots in supported servers
• All PMem modules operate the following speeds:
  • With 4-Socket capable processors: PMem modules operate at 2666 MHz. Installed memory DIMMs will also operate at 2666 MHz.
  • With 2-Socket-capable processors: PMem modules operate at 3200 MHz. Installed memory DIMMs will also operate at 3200 MHz.
• Optional data encryption using AES 256-bit encryption
• Optional data security in App Direct mode, including secure erase functionality
• Firmware updates through XClarity Administrator and other Lenovo support tools

PMem modules offer the following memory protection technologies:

• ECC
• Device failure recovery - SDDC
• Die sparing - DDDC
• Patrol scrubbing

Demand scrubbing is not supported.

The following figure shows PMem modules and TruDDR4 DIMMs installed in a ThinkSystem SR850 V2 server. In this full configuration, there is one PMem module and one TruDDR4 DIMM installed in each memory channel (6 PMem modules and 6 DIMMs per processor).

Figure 2. Intel Optane PMem 200 Series modules installed in a ThinkSystem SR850 V2 server

The following are the requirements when selecting the number of DIMMs and PMem modules:

• PMem 200 Series modules require third-generation Intel Xeon Scalable Family processors.
  • First and second-generation Xeon Scalable processors are not supported.
• For each memory channel with both a PMem module and a TruDDR4 DIMM installed, the PMem module is installed in channel slot 1 (closest) and the DIMM is installed in channel slot 0
• To maximize performance, balance all memory channels
• All installed PMem modules must be the same size. Mixing PMem modules of different capacities is not supported
• All installed DIMMs must be the same size and structure (ie same part number). Mixing different DIMMs is not supported
• For 4-socket-capable ("Cooper Lake") processors used in SR860 V2 and SR850 V2 servers:
  • All Platinum processors and all Gold processors support PMem module.
  • Maximum 6 PMem modules per processor (Maximum 1 PMem in each memory channel)
  • With PMem installed in the system, a minimum 6 RDIMMs per processor is required
  • For each memory channel with both a PMem module and an RDIMM installed, the PMem module is installed in channel slot 1 (closest) and the DIMM is installed in channel slot 0
  • To maximize performance, balance all memory channels
  • Memory sparing and memory mirroring are not supported with PMem modules installed
• For 2-socket-capable ("Ice Lake") processors used in all other ThinkSystem V2 servers:
  • Platinum processors, Gold processors, and the Silver 4314 processor all support PMem
  • Maximum of 8 PMem modules processor (Maximum 1 PMem in each memory channel)
  • With PMem installed in the system, a minimum 4 RDIMMs per processor is required
  • Memory sparing and memory mirroring are not supported with PMem modules installed
  • Intel Total Memory Encryption (TME) is not supported and must be disabled
  • Intel Software Guard Extensions (SGX) is not supported and must be disabled

App Direct Mode is supported both by 4-socket Xeon SP Gen 3 servers (SR860 V2 and SR850 V2 servers) and 2-socket Xeon SP Gen 3 processors (all other V2 servers).

4-socket server support

In App Direct Mode in the SR860 V2 and SR850 V2, only the combinations of RDIMMs and PMem modules listed in the following table are supported. A required RDIMM:PMem density ratio of between 1:1 and 1:4 must be met.

2-socket server support

In App Direct Mode in the 2-socket ThinkSystem V2 servers, only the combinations of RDIMMs and PMem modules listed in the following table are supported. A required RDIMM:PMem ratio of between 1:1 and 1:8 must be met.

Memory Mode is only supported by 2-socket ThinkSystem V2 servers. The 4-socket servers (SR860 V2 and SR850 V2 servers) do not support Memory Mode.

2-socket server support

In Memory Mode, the PMem modules are seen by the operating system as system memory. The memory DIMMs are hidden from the operating system and are used as a high-speed cache for the PMem modules.

The specific memory part numbers that are supported with PMem modules is listed in the Memory DIMM support section.

* In Memory Mode, the available memory = persistent memory installed. The actual user capacity of PMem modules is less than the stated amount. For example, a 128GB PMem module has 126.7GB usable storage.
† Ratio of system memory to persistent memory, RDIMM:PMem; Memory Mode only supports DIMM:Pmem ratios of between 1:4 and 1:16

The following table lists which TruDDR4 RDIMMs can be installed with PMem modules. RDIMMs will operate up to 2666 MHz when installed with PMem modules and 4-socket-capable processors. RDIMMs will operate up to 3200 MHz when installed with PMem modules and 2-socket-capable processors.

The following tables list the ThinkSystem servers that are compatible.

The following tables list the supported operating systems:

• ThinkSystem 128GB TruDDR4 3200MHz (1.2V) Intel Optane Persistent Memory, 4ZC7A08732
• ThinkSystem 256GB TruDDR4 3200MHz (1.2V) Intel Optane Persistent Memory, 4ZC7A08734
• ThinkSystem 512GB TruDDR4 3200MHz (1.2V) Intel Optane Persistent Memory, 4ZC7A08736

The ThinkSystem Intel Optane Persistent Memory Modules carry a 1-year limited warranty. When installed in a supported ThinkSystem server, the PMem modules assume the server’s base warranty and any warranty upgrades.