HPE XD685 vs Lenovo SR650 V4
A specification-by-specification comparison of the HPE ProLiant Compute XD685 and the Lenovo ThinkSystem SR650 V4, built from HPE’s and Lenovo’s own documents. 1 headline measure favours the XD685, 6 favour the SR650 V4, and they share no processors.
Bottom line. SR650 V4 leads on virtualisation, databases and in-memory work, storage density, AI and acceleration, network throughput. 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 XD685 if…
- Cores, fully populated: 192 against 172 on the SR650 V4
- Four eight-GPU boards on one platform — NVIDIA HGX H200, B200 and HGX B300, or AMD Instinct MI355X — with B200, B300 and MI355X each tied to its own DLC or power kit.
Choose the SR650 V4 if…
- Memory ceiling: 8 TB against 3 TB on the XD685
- Drive bays: 40 against 12 on the XD685
- Accelerators: Up to 10 against Up to 8 on the XD685
- Up to 36 NVMe drives — 24 front, 8 mid and 4 rear — connect straight to the processors on a full x4 link each, so an all-flash build needs no retimer adapters.
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 | XD685 | SR650 V4 |
|---|---|---|
| Processors listed | 9 | 27 |
| Most cores per processor | 96 | 86 |
| Highest processor TDP | 400 W | 350 W |
| Processor families | AMD EPYC 9005 | Xeon 6 P-core |
| Single-processor option | No | Yes |
Memory
| Specification | XD685 | SR650 V4 |
|---|---|---|
| DIMM slots | 24 | 32 |
| Slots per processor | 12 | 16 |
| Largest module listed | 128 GB | 256 GB |
| Fastest rated speed | 6,400 MT/s | 8,000 MT/s |
| Memory types | RDIMM DDR5-6400 | RDIMM DDR5-6400 · 3DS RDIMM DDR5-6400 · MRDIMM DDR5-8000 (8800 rated) · CXL 2.0 E3.S 2T memory modules |
Storage
Bay counts are the maximum each document states, including rear and mid-chassis positions.
| Specification | XD685 | SR650 V4 |
|---|---|---|
| Maximum bays | 12 | 40 |
| Documented layouts | 2 | 16 |
| Bay sizes | E3.S | 3.5-inch · 2.5-inch · E3.S |
| Boot devices | HPE ProLiant Compute XD NS204i-u 960GB Boot Device (S4R99A) - 2x 480 GB M.2 NVMe RAID 1 · HPE ProLiant Compute XD NS204i-u 2x 960GB Boot Device (S6A36A) - 2x 960 GB M.2 NVMe RAID 1 | Internal M.2 RAID B550i-2i SATA/NVMe Enablement Kit (2 x M.2 NVMe, integrated Broadcom RAID) · Internal M.2 RAID B545i-2i SATA/NVMe Adapter (2 x M.2 SATA/NVMe, integrated Broadcom RAID) · Internal M.2 B350i-2i NVMe Enablement Kit (2 x M.2 NVMe x2, VROC RAID) + 4 more |
| Storage controllers | 3 | 24 |
Accelerators & I/O
| Specification | XD685 | SR650 V4 |
|---|---|---|
| Accelerators supported | Up to 8 | Up to 10 |
| Double-wide cards listed | 0 | 2 |
| OCP slots | 0 | 2 |
| PCIe network slots | 12 | 10 |
| Network cards listed | 20 | 31 |
Power & platform
| Specification | XD685 | SR650 V4 |
|---|---|---|
| Power-supply options | 1 | 14 |
| Output range | 3,000–3,000 W | 800–3,200 W |
| Input types | −48 V DC | AC · 277 VAC / HVDC · −48 V DC |
| Management | HPE iLO 6 | XClarity Controller 3 |
| Chassis depthVendors measure depth differently — see each data sheet | 1049 mm (L) deep | 796 mm |
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.
XD685: processors by cores and TDP
SR650 V4: processors by cores and TDP
XD685: memory with every slot filled
SR650 V4: memory with every slot filled
XD685: drive bays
Front panel
8 × EDSFF NVMe at the front — 8 bays in total.
SR650 V4: drive bays
Front panel
12 × 3.5" SAS/SATA at the front — 12 bays in total.
XD685: power supplies
SR650 V4: power supplies
XD685 vs SR650 V4, answered
Is the XD685 or the SR650 V4 the faster server?
Neither document publishes benchmark results, so this page compares what they do state. The XD685 lists 9 processors up to 96 cores at 400 W; the SR650 V4 lists 27 up to 86 cores at 350 W. Fully populated that is 192 cores against 172.
Which holds more memory?
The XD685 has 24 DIMM slots and a stated ceiling of 3.0 TB. The SR650 V4 has 32 and 8 TB.
Which takes more drives?
XD685: 12 bays across 2 documented layouts. SR650 V4: 40 across 16. Counts include rear and mid-chassis positions where the vendor documents them.
Can either take GPUs?
XD685: up to 8 accelerators, 0 double-wide cards listed. SR650 V4: up to 10, 2 double-wide listed.
Do they share any processors?
No. The two documents list different processors, so a like-for-like processor build is not possible across these two.
Where these figures come from. XD685: HPE ProLiant Compute XD685 QuickSpecs (V15 - 03-August-2026) (HPE document). SR650 V4: Lenovo ThinkSystem SR650 V4 Server (September 8, 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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