HPE DDR4 SmartMemory delivers great performance, reliability, and efficiency. Our large selection of server memory solutions provides the compatibility, capacity, and bandwidth you need to productively manage your expanding workload with the HP ProLiant Gen9 and Gen10 server, Apollo Family, Synergy, and Blade Systems.
The HPE 850882-001 64GB Server SmartMemory 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 controller's 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 ProLiant server.
Substitute PN: 
 815101-B21
 840759-091
840759-691
HMAA8GL7AMR4N-VK
Compatible With:
 HPE Proliant BL Series: BL460c (G10) Blade Servers
 HPE Proliant DL Series: DL360 (G10) DL380 (G10) DL560 (G10) DL580 (G10) Rack Servers
 HPE Proliant ML Series: ML350 (G10) Tower Server
 HPE Proliant XL Series: XL230k (G10) Server