The HPE 805358-B21 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.
  
 HPE DDR4 server memory delivers great performance, reliability, efficiency, and security. Our large selection of server memory solutions provides the compatibility, capacity, and bandwidth users need to productively manage users expanding workload with HPE ProLiant Gen9, Gen10, and Gen10 Plus servers, Apollo family servers, Synergy systems, and Blade systems.
  
 Substitute PN:
 819413-001
 809085-091 
 Compatible With:
 HPE ProLiant DL60 G9, DL80 G9
 HPE ProLiant BL460C G9, BL660C G9
 HPE ProLiant DL120 G9, DL160 G9, DL180 G9
 HPE ProLiant DL360 G9, DL380 G9, DL388 G9
 HPE ProLiant DL560 G9, DL580 G9
 HPE ProLiant ML110 G9, ML150 G9, ML350 G9
 HPE ProLiant XL170R G9, XL190R G9, XL230A G9, XL250A G9, XL230B G9
 HPE ProLiant WS460C G9
 HPE Apollo 2000, 4200, 4500, 6000