eXFlash DIMMs
This topic provides information about eXFlash DIMM installation and requirements.
The Lenovo System x3850 X6 and x3950 X6 server provides support for eXFlash™ DIMMs. You can use eXFlash DIMMs in unused DIMM slots for solid state drive storage on the server. For more information and notes about installing DIMMs, see Installing a memory module. eXFlash DIMMs are only supported in Independent memory mode. For more information about DIMM installation sequence for Independent memory mode, see Independent memory mode. The DIMM installation order for eXFlash DIMMs follows the independent mode (performance) installation order.
When you install an eXFlash DIMM, consider the following information:
- RDIMMs must be installed in the server with eXFlash DIMMs. You cannot install all eXFlash DIMMs in the server.
- RDIMMs must be installed first, then eXFlash DIMMs can be installed.
- When you install eXFlash DIMMs, do not leave an empty DIMM slot between installed DIMMs.
- For both the 4-socket and 8-socket configurations, one eXFlash DIMM can be installed in each DDR3 or DDR4 channel. A maximum of 8 eXFlash DIMMs can be installed in each compute book. A maximum of 32 eXFlash DIMMs can be installed in the server. In the 8-socket configuration of the server, the eXFlash DIMMs must be installed in the bottom node only.
- Mixing of LRDIMMs and eXFlash DIMMs in the same server is not supported.
- eXFlash DIMMs are supported in Independent memory mode only.
- eXFlash DIMMs are not supported in Lockstep memory mode, memory mirroring, or memory rank sparing.
- You can install any configuration of the supported eXFlash DIMMs (up to 32 eXFlash DIMMs) in the server.
- The same level of firmware should be installed on all eXFlash DIMMs in the server.
- When you install eXFlash DIMMs in the server, see
Environment
in the Server features and specifications section for the supported environment information for eXFlash DIMMs. - If you install eXFlash DIMMs on the Red Hat and SLES operating systems, keep in mind that the server supports only Red Hat Enterprise Linux version 6.5 or later and SUSE Linux Enterprise Server (SLES) version 11 SP3 or later operating systems. For more information about eXFlash DIMMs, go to the eXFlash DIMM Configuration and Support Requirements website.
The following table lists the supported eXFlash DIMMs specifications:
| Storage | SDRAM Equivalent Capacity | SDRAM Equivalent Density | SDRAM Equivalent Ranks | SDRAM Equivalent Organization | Form factor | Voltage | Type | Bandwidth (MHz) |
|---|---|---|---|---|---|---|---|---|
| 200 GB eXFlash DIMM | 8 GB | 4 Gb | 1R | 1024Mb x 4 | DDR3 Low profile | 1.35V | RDIMM | 1600 MHz |
| 400 GB eXFlash DIMM | 8 GB | 4 Gb | 1R | 1024Mb x4 | DDR3 Low profile | 1.35V | RDIMM | 1600 MHz |
When you install eXFlash DIMMs, follow the same installation order for the Independent memory mode with mirroring disabled as shown in the following table:
| DIMM installation order | Independent mode with memory mirroring disabled | Independent mode with memory mirroring enabled |
|---|---|---|
| 1 | DIMM connector 9 | DIMM connectors 9 and 19 |
| 2 | DIMM connector 6 | DIMM connectors 6 and 16 |
| 3 | DIMM connector 1 | DIMM connectors 1 and 15 |
| 4 | DIMM connector 10 | DIMM connectors 10 and 24 |
| 5 | DIMM connector 15 | DIMM connectors 8 and 20 |
| 6 | DIMM connector 24 | DIMM connectors 5 and 17 |
| 7 | DIMM connector 19 | DIMM connectors 2 and 14 |
| 8 | DIMM connector 16 | DIMM connectors 11 and 23 |
| 9 | DIMM connector 8 | DIMM connectors 7 and 21 |
| 10 | DIMM connector 5 | DIMM connectors 4 and 18 |
| 11 | DIMM connector 2 | DIMM connectors 3 and 13 |
| 12 | DIMM connector 11 | DIMM connectors 12 and 22 |
| 13 | DIMM connector 14 | |
| 14 | DIMM connector 23 | |
| 15 | DIMM connector 20 | |
| 16 | DIMM connector 17 | |
| 17 | DIMM connector 7 | |
| 18 | DIMM connector 4 | |
| 19 | DIMM connector 3 | |
| 20 | DIMM connector 12 | |
| 21 | DIMM connector 13 | |
| 22 | DIMM connector 22 | |
| 23 | DIMM connector 21 | |
| 24 | DIMM connector 18 |