{"product_id":"hpe-256gb-16x16gb-ddr3-1866-rdimm-kit-708641-256","title":"HPE 256GB (16 x 16GB) 1866MHz DDR3 PC3-14900 ECC Registered CL13 240-Pin DIMM 1.5V Dual Rank x4 Memory Kit - 708641-256","description":"\u003cp\u003eThe 708641-256 is a set of sixteen HPE 16GB DDR3-1866 RDIMMs that add up to 256GB. Each module matches HPE option part 708641-B21: dual rank x4, CAS 13, registered. They are made for ProLiant Gen8 servers.\u003c\/p\u003e\n\u003ch2\u003eWhat sixteen modules fill\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eServer\u003c\/th\u003e\n\u003cth\u003eSlots\u003c\/th\u003e\n\u003cth\u003eUsed by this set\u003c\/th\u003e\n\u003cth\u003eOpen slots\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eBL460c Gen8 blade\u003c\/th\u003e\n\u003ctd\u003e16\u003c\/td\u003e\n\u003ctd\u003e16\u003c\/td\u003e\n\u003ctd\u003e0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eDL360p Gen8\u003c\/th\u003e\n\u003ctd\u003e24\u003c\/td\u003e\n\u003ctd\u003e16\u003c\/td\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eDL380p Gen8\u003c\/th\u003e\n\u003ctd\u003e24\u003c\/td\u003e\n\u003ctd\u003e16\u003c\/td\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003eOn a two-processor Gen8 server, each CPU has four memory channels. Eight modules per CPU put two on every channel, which keeps the layout even. HPE's population guide for your model shows the slot layout.\u003c\/p\u003e\n\u003ch2\u003eThe 1866 speed rule\u003c\/h2\u003e\n\u003cp\u003eDDR3-1866 needs Xeon E5-2600 v2 processors. First-generation E5-2600 CPUs top out at 1600, so these modules slow down to match. A mixed set also falls to the speed of its slowest module.\u003c\/p\u003e\n\u003cp\u003eThe eight open slots in a DL380p Gen8 can take eight more matching modules later. A full 24-slot server then holds 384GB.\u003c\/p\u003e\n\u003ch2\u003eVoltage\u003c\/h2\u003e\n\u003cp\u003eThis is standard-voltage memory at 1.5V. Low-voltage modules, marked PC3L, run at 1.35V. If the two types mix, the server usually runs every module at 1.5V.\u003c\/p\u003e\n\u003ch2\u003eReading the HPE name\u003c\/h2\u003e\n\u003cp\u003eHPE calls the single module \"16GB (1x16GB) Dual Rank x4 PC3-14900R (DDR3-1866) Registered CAS-13 Memory Kit\". PC3-14900 means 14.9 GB\/s per module. HPE's spare number for each module is 715274-001.\u003c\/p\u003e\n\u003ch2\u003eIs 708641-256 an HPE number?\u003c\/h2\u003e\n\u003cp\u003eHPE's own option number for one module is 708641-B21. The 708641-256 number names a set of sixteen of them. Search either one and you find the same modules.\u003c\/p\u003e\n\u003ch2\u003eQuick answers\u003c\/h2\u003e\n\u003ch3\u003eCan these go in a Gen9 server?\u003c\/h3\u003e\n\u003cp\u003eNo. Gen9 servers use DDR4 memory, and DDR3 modules don't fit DDR4 slots.\u003c\/p\u003e\n\u003ch3\u003eDo they work in a desktop?\u003c\/h3\u003e\n\u003cp\u003eNo. Registered ECC modules need a server board.\u003c\/p\u003e\n\u003ch3\u003eWhat does CAS 13 mean?\u003c\/h3\u003e\n\u003cp\u003eIt is the number of clock cycles between a read command and the first data. Lower is quicker at the same speed.\u003c\/p\u003e\n\u003ch3\u003eAre they LRDIMMs?\u003c\/h3\u003e\n\u003cp\u003eNo. They are registered modules with a register chip and no data buffers.\u003c\/p\u003e\n\u003ch2\u003e708641-256 specifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eHPE\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eSet part number\u003c\/th\u003e\n\u003ctd\u003e708641-256\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eModule option part\u003c\/th\u003e\n\u003ctd\u003e708641-B21 (sixteen of them)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eSpare part per module\u003c\/th\u003e\n\u003ctd\u003e715274-001\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eTotal capacity\u003c\/th\u003e\n\u003ctd\u003e256GB (16 x 16GB)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eType\u003c\/th\u003e\n\u003ctd\u003eDDR3 RDIMM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eSpeed\u003c\/th\u003e\n\u003ctd\u003e1866 MT\/s (PC3-14900)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eRank\u003c\/th\u003e\n\u003ctd\u003eDual rank x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eCAS latency\u003c\/th\u003e\n\u003ctd\u003eCL13\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eVoltage\u003c\/th\u003e\n\u003ctd\u003e1.5V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003ePins\u003c\/th\u003e\n\u003ctd\u003e240\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eFits\u003c\/th\u003e\n\u003ctd\u003eProLiant Gen8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"HP","offers":[{"title":"Default Title","offer_id":62811022918003,"sku":"708641-256","price":1132.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0992\/9546\/1747\/files\/708641-256.jpg?v=1778021539","url":"https:\/\/cpurepublic.com\/products\/hpe-256gb-16x16gb-ddr3-1866-rdimm-kit-708641-256","provider":"CPU Republic LLC","version":"1.0","type":"link"}