Dell XE9712 vs Lenovo SC777 V4 Neptune
A specification-by-specification comparison of the Dell PowerEdge XE9712 and the Lenovo ThinkSystem SC777 V4 Neptune, built from Dell’s and Lenovo’s own documents. None of the headline measures favour the XE9712; 2 favour the SC777 V4 Neptune, and 1 processors appear in both lists.
Bottom line. SC777 V4 Neptune leads on storage density. Neither vendor publishes benchmarks for these machines, so every call here is made on what their documents state.
The measures that decide it
Each row is a figure both vendors publish. Bars show the split between the two; a badge marks the larger figure, which is not always the better buy — a shallower chassis or a lower power ceiling can matter more.
Which one, and why
Drawn from the measures above and each model’s own data sheet. Neither vendor publishes benchmark results for these servers, so nothing here claims one is “faster”.
Choose the XE9712 if…
- Four 288 GB Blackwell Ultra GPUs and two Grace CPUs per 1U sled, with rear NVLink connectors into the rack’s NVLink switches; Dell’s spec sheet puts up to 72 GPUs in one NVLink rack with 1.8 TB/s of GPU-to-GPU bandwidth.
Choose the SC777 V4 Neptune if…
- Drive bays: 10 against 8 on the XE9712
- Largest power supply: 15,000 W against 5,500 W on the XE9712
- Two GB200 NVL4 boards put four B200 GPUs and two Grace processors in one tray; NVLink joins the GPUs in a 1.8 TB/s full mesh, and each GPU has 450 GB/s of NVLink to the processors.
Where each one pulls ahead
Calls made on documented capacity only — cores, memory, bays, accelerators and network options — with the figures behind each one shown.
Side by side, differences first
Everything both documents state, grouped. The default view hides rows where the two machines are identical.
Processors
Every processor each vendor lists for the model, from its own document.
| Specification | XE9712 | SC777 V4 Neptune |
|---|---|---|
| Highest processor TDP | 500 W | 300 W |
Memory
| Specification | XE9712 | SC777 V4 Neptune |
|---|---|---|
| Largest module listed | 480 GB | 128 GB |
| Fastest rated speed | — | 4,266 MT/s |
| Memory types | LPDDR5X soldered (ECC) · HBM3e (GPU) | LPDDR5X ECC 4266 MT/s (soldered, fixed 960 GB) · HBM3e (186 GB per GPU) |
Storage
Bay counts are the maximum each document states, including rear and mid-chassis positions.
| Specification | XE9712 | SC777 V4 Neptune |
|---|---|---|
| Maximum bays | 8 | 10 |
| Boot devices | M.2 boot riser (1 x M.2 2280 NVMe Gen4 SSD, no RAID; thermal config lists 960 GB M.2 NVMe x 1) | 2 x E3.S 1T NVMe boot drives (bays 0-1) via ThinkSystem SC777 V4 Neptune PCIe Switch Board for Boot Drives (feature C51T), switched x4 to CPU 2 |
| Storage controllers | 2 | 1 |
Accelerators & I/O
| Specification | XE9712 | SC777 V4 Neptune |
|---|---|---|
| PCIe network slots | 2 | 6 |
Power & platform
| Specification | XE9712 | SC777 V4 Neptune |
|---|---|---|
| Output range | 5,500–5,500 W | 15,000–15,000 W |
| Management | OpenBMC on Aspeed AST2600 | XClarity Controller 3 |
| Chassis depthVendors measure depth differently — see each data sheet | sled 807 mm (31.77 in) deep, 438 mm wide, 43.6 mm high, 30 kg | 760 mm tray depth |
Processors, memory, bays and power
The same charts each data sheet carries, drawn to the same scale so the two ranges can be read against each other.
XE9712: processors by cores and TDP
SC777 V4 Neptune: processors by cores and TDP
XE9712: memory
960 GB LPDDR5X (ECC) total per sled - 480 GB per CPU, solder-down on each GB300 HPM (2 HPMs per sled) + 288 GB HBM3e per GPU
SC777 V4 Neptune: memory
960 GB LPDDR5X (CPU) + 744 GB HBM3e (GPU)
XE9712: drive bays
Front panel
8 × EDSFF NVMe at the front — 8 bays in total.
SC777 V4 Neptune: drive bays
Front panel
2 × EDSFF NVMe at the front — 2 bays in total.
XE9712: power supplies
SC777 V4 Neptune: power supplies
1 processors you can order in either
Both vendor documents list these parts, so a build can be matched across the two and the comparison comes down to the chassis: 0 more are exclusive to the XE9712 and 0 to the SC777 V4 Neptune.
| Processor | Cores | TDP |
|---|---|---|
| NVIDIA Grace (Grace Ultra, 72 cores) | 72 | 500 W |
XE9712 vs SC777 V4 Neptune, answered
Is the XE9712 or the SC777 V4 Neptune the faster server?
Neither document publishes benchmark results, so this page compares what they do state. The XE9712 lists 1 processors up to 72 cores at 500 W; the SC777 V4 Neptune lists 1 up to 72 cores at 300 W. Fully populated that is 144 cores against 144.
Which holds more memory?
The XE9712 has 0 DIMM slots and a stated ceiling of 960 GB LPDDR5X. The SC777 V4 Neptune has 0 and 960 GB LPDDR5X.
Which takes more drives?
XE9712: 8 bays across 1 documented layouts. SC777 V4 Neptune: 10 across 1. Counts include rear and mid-chassis positions where the vendor documents them.
Can either take GPUs?
XE9712: up to 4 accelerators, 0 double-wide cards listed. SC777 V4 Neptune: up to 4, 0 double-wide listed.
Do they share any processors?
Yes — 1 processor appears in both documents, including the NVIDIA Grace (Grace Ultra, 72 cores). That makes a like-for-like build possible on either server.
Where these figures come from. XE9712: Dell PowerEdge XE9712 Technical Guide (Rev. A00, November 2025) (Dell document). SC777 V4 Neptune: Lenovo ThinkSystem SC777 V4 Neptune Server (July 15, 2026) (Lenovo document). Each claim on this page is derived from those documents, checked page by page on the two data sheets, and carries no pricing.
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