HPE ProLiant BL685c G7 Memory
Genuine HPE DDR3 memory for the HPE ProLiant BL685c G7, new and refurbished. This blade carries 32 Registered DIMM slots — eight behind each of its four processors, four channels of two slots each — and sixteen of them are dead the moment the blade is running two processors instead of four.
BL685c G7 Memory Specifications
- Type: DDR3 Registered (RDIMM), PC3-10600 (DDR3-1333) and PC3-8500 (DDR3-1066), including PC3L low-voltage parts
- Slots: 32 in total, eight per processor across four channels at two DIMMs per channel; with only two of the four processors fitted, half the slots are unavailable
- Documented maximum: 1TB, using 32GB modules in all 32 slots — quad-rank Registered at 1066MHz, or Load Reduced at 1333MHz
- Reachable from the kits listed here: 512GB, using 16GB quad-rank PC3-8500 Registered modules in all 32 slots
- Rank limit: a maximum of eight ranks per channel, which is two quad-rank DIMMs per channel
- Mixing: Registered and Load Reduced DIMMs cannot be mixed; different speeds can be, and the blade settles on a common speed; mixing 1.5V and 1.35V modules runs the whole bank at the higher voltage
Two processors means sixteen dead DIMM slots. This blade has 32 slots, eight behind each of its four sockets, and a module in a slot belonging to an absent processor does nothing at all. Fill the other two sockets before buying memory that has nowhere to go — on two processors, the 512GB ceiling on this page is 256GB.
How Far Does Each DIMM Size Go in 32 Slots?
| Kit stocked | Rank | Rated speed | Four processors, 32 slots | Two processors, 16 slots |
|---|---|---|---|---|
| 4GB PC3-10600 and PC3L-10600 | Single rank | DDR3-1333 | 128GB | 64GB |
| 8GB PC3-10600 and PC3L-10600 | Dual rank | DDR3-1333 | 256GB | 128GB |
| 16GB PC3-8500 | Quad rank | DDR3-1066 | 512GB | 256GB |
The 1TB figure in the QuickSpecs needs 32GB modules, and those come as quad-rank Registered or as Load Reduced parts that run only on Opteron 6200 and 6300 series processors. The kits on this page stop at 16GB, so 512GB is the honest ceiling here, and only with all four sockets filled. A blade on two processors halves every number in the table above.
Choosing the Right BL685c G7 Memory
- Count the processors before counting the slots. A DIMM in a slot belonging to an absent processor does nothing, and HPE asks for a minimum of one DIMM for every processor installed.
- Rank sets the speed, not capacity. The memory bus holds 1333MHz with one quad-rank DIMM or two single-rank or dual-rank DIMMs per channel, and falls to 1066MHz with two quad-rank DIMMs per channel.
- Low-voltage PC3L runs a step slower. The parts listing states that the bus drops one speed grade when 1.35V memory is installed, so a PC3L kit is a power decision rather than a performance one.
- Balance across processors and across channels. HPE asks for total capacity spread evenly between the installed processors, and then evenly across the four channels on each one.
- Every kit here is a single DIMM. A 256GB build is 32 kits, not one boxed set, and virtualization workloads want at least two DIMMs per processor.
Complete Your BL685c G7 Build
Memory capacity is gated by socket count on this blade — see BL685c G7 processors before ordering past sixteen modules. For the rest of the blade, browse BL685c G7 hard drives and storage controllers, or start from the full BL685c G7 parts listing and the wider HPE parts by server model index. Background reading: understanding memory rank in HPE servers and the importance of memory speed.
BL685c G7 Memory FAQ
What is the maximum memory in a BL685c G7?
The QuickSpecs document 1TB, reached with 32GB modules in all 32 slots, either quad-rank Registered at 1066MHz or Load Reduced at 1333MHz. The Registered kits listed on this page reach 512GB with 16GB modules.
How many memory slots does the BL685c G7 have?
Thirty-two: eight behind each of the four processor sockets, arranged as four channels with two DIMM slots each. With only two processors fitted, sixteen of them are unavailable.
Can I use LRDIMMs in a BL685c G7?
Only with Opteron 6200 or 6300 series processors, and never alongside Registered DIMMs. HPE does not support mixing Registered and Load Reduced memory in the same blade.
Why is my BL685c G7 memory running at 1066MHz?
Ranks per channel. The bus holds 1333MHz with one quad-rank DIMM or two single-rank or dual-rank DIMMs per channel, and falls to 1066MHz with two quad-rank DIMMs per channel. Low-voltage PC3L modules run one grade slower again.
Do HPE memory kits for this blade contain more than one DIMM?
No. Every DDR3 option kit listed for this blade is a single DIMM, so filling all 32 slots means 32 kits. HPE also requires at least one DIMM for each processor installed.
Can I mix 4GB and 8GB DIMMs in a BL685c G7?
Different capacities and speeds can be mixed and the blade will select a common speed, but HPE asks you to balance total capacity between the processors and across each processor's four channels. Mixing 1.5V and 1.35V modules runs everything at the higher voltage.
✅ Looking for a specific BL685c G7 memory module? Browse our full selection below.
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