The 647885-B21 32GB LRDIMM from HPE is a great option when looking to improve the performance of your ProLiant servers and data centers. Infrastructure matters, it's the foundation for all the information and applications of your business. You trust ProLiant's quality for its reliability and performance to keep your infrastructure running. Server memory is one of the most critical components; even the slightest defect can result in downtime that could shut down your business. Choosing the HPE 647885-B21 server memory option ensures that you will receive the same quality integration reliability and confidence that come with all Proliant Services.
The HPE 647885-B21 DDR3 SDRAM is a Load-Reduced DIMM (LRDIMM), an LRDIMM is similar to a registered DIMM (RDIMM) in that it buffers electrical load on the memory controller. However, instead of plugging directly into the parallel memory bus that is connected to the memory controllers processors, the LRDIMM can navigate outside of these restrictions through the use of the Memory Buffer chips. When a server is exclusively configured with LRDIMMs, the memory controllers in the processors automatically shift to Serial Mode - all data, command, and control signals become packetized and transmitted to the Memory Buffer on the LRDIMMs. The Memory Buffer then handles all the Reads and Writes to the DRAM chips.
LRDIMMs greatly reduce the electrical loading of the DRAM chips onto the memory bus, and through a process called "Rank Multiplication," transform a Quad Rank LRDIMM into a Dual Rank memory module for the memory controller. Through the reduction of the electrical Ranks of the LRDIMM, the server is then able to support LRDIMMs at higher speeds than RDIMMs, and with fewer restrictions on sockets. This means using LRDIMMs you can configure systems with the largest possible memory footprints. If large quantities of RAM are your goal, then using a system full of LRDIMMs RAM can help you achieve twice the capacity for your server System.
Substitute PN:
647654-181
 687466-001
 HMT84GL7AMR4A-H9
Compatible With:
 HPE ProLiant DL385p Gen8 Server
 HPE ProLiant DL585 Gen7 Server
 HPE ProLiant BL685c Gen7 Server Blade
 HPE ProLiant BL465c Gen8 Server Blade