Dell R6725 vs Lenovo SR645 V3
A specification-by-specification comparison of the Dell PowerEdge R6725 and the Lenovo ThinkSystem SR645 V3, built from Dell’s and Lenovo’s own documents. 2 headline measures favour the R6725, 1 favours the SR645 V3, and 18 processors appear in both lists.
Bottom line. R6725 leads on virtualisation, storage density. SR645 V3 leads on AI and acceleration. 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 R6725 if…
- Cores, fully populated: 384 against 320 on the SR645 V3
- Drive bays: 22 against 16 on the SR645 V3
- Two EPYC 9005 sockets in 1U, each up to 192 cores with the EPYC 9965 — 384 cores in a single rack unit.
Choose the SR645 V3 if…
- Accelerators: Up to 5 against Up to 3 on the R6725
- Two EPYC sockets in one rack unit: a pair of 160-core 9845s gives 320 cores, and each processor drives its own 12 DDR5 channels.
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 | R6725 | SR645 V3 |
|---|---|---|
| Processors listed | 20 | 46 |
| Most cores per processor | 192 | 160 |
| Highest processor TDP | 500 W | 400 W |
| Processor families | AMD EPYC 9005 | AMD EPYC 9005 · AMD EPYC 9004 |
| Single-processor option | No | Yes |
Memory
| Specification | R6725 | SR645 V3 |
|---|---|---|
| Memory types | RDIMM DDR5-6400 | RDIMM DDR5-6400 (5th Gen EPYC) · RDIMM DDR5-4800 (4th Gen EPYC) · 9x4 RDIMM · 3DS RDIMM DDR5-6400 |
Storage
Bay counts are the maximum each document states, including rear and mid-chassis positions.
| Specification | R6725 | SR645 V3 |
|---|---|---|
| Maximum bays | 22 | 16 |
| Documented layouts | 8 | 19 |
| Bay sizes | 3.5-inch · 2.5-inch · E3.S | 3.5-inch · E3.S · 2.5-inch |
| Boot devices | BOSS-N1 DC-MHS (RAID 0/1, 2 x M.2 NVMe 480 GB or 960 GB read-intensive) | M.2 SATA/NVMe 2-Bay Enablement Kit (4Y37A09738) · M.2 SATA/x4 NVMe 2-Bay Adapter (4Y37A79663) · M.2 NVMe 2-Bay RAID Adapter (4Y37A09750) + 1 more |
| Storage controllers | 5 | 18 |
Accelerators & I/O
| Specification | R6725 | SR645 V3 |
|---|---|---|
| Accelerators supported | Up to 3 | Up to 5 |
| OCP slots | 2 | 1 |
| PCIe network slots | 3 | 5 |
| Network cards listed | 15 | 30 |
Power & platform
| Specification | R6725 | SR645 V3 |
|---|---|---|
| Output range | 800–1,800 W | 750–1,800 W |
| Input types | AC · 277 VAC / HVDC | AC · −48 V DC |
| Management | iDRAC10 | XClarity Controller 2 |
| Chassis depthVendors measure depth differently — see each data sheet | 815.14 mm without bezel / 816.92 mm with bezel | — |
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.
R6725: processors by cores and TDP
SR645 V3: processors by cores and TDP
R6725: memory with every slot filled
SR645 V3: memory with every slot filled
R6725: drive bays
Front panel
20 × EDSFF NVMe at the front — 20 bays in total.
SR645 V3: drive bays
Front panel
16 × EDSFF NVMe at the front — 16 bays in total.
R6725: power supplies
SR645 V3: power supplies
18 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: 2 more are exclusive to the R6725 and 28 to the SR645 V3.
| Processor | Cores | TDP |
|---|---|---|
| AMD EPYC 9845 | 160 | 390 W |
| AMD EPYC 9825 | 144 | 390 W |
| AMD EPYC 9745 | 128 | 400 W |
| AMD EPYC 9655 | 96 | 400 W |
| AMD EPYC 9575F | 64 | 400 W |
| AMD EPYC 9535 | 64 | 300 W |
| AMD EPYC 9555 | 64 | 360 W |
| AMD EPYC 9475F | 48 | 400 W |
| AMD EPYC 9455 | 48 | 300 W |
| AMD EPYC 9355 | 32 | 280 W |
| AMD EPYC 9375F | 32 | 320 W |
| AMD EPYC 9335 | 32 | 210 W |
R6725 vs SR645 V3, answered
Is the R6725 or the SR645 V3 the faster server?
Neither document publishes benchmark results, so this page compares what they do state. The R6725 lists 20 processors up to 192 cores at 500 W; the SR645 V3 lists 46 up to 160 cores at 400 W. Fully populated that is 384 cores against 320.
Which holds more memory?
The R6725 has 24 DIMM slots and a stated ceiling of 6 TB. The SR645 V3 has 24 and 6 TB.
Which takes more drives?
R6725: 22 bays across 8 documented layouts. SR645 V3: 16 across 19. Counts include rear and mid-chassis positions where the vendor documents them.
Can either take GPUs?
R6725: up to 3 accelerators, 0 double-wide cards listed. SR645 V3: up to 5, 0 double-wide listed.
Do they share any processors?
Yes — 18 processors appear in both documents, including the AMD EPYC 9845. That makes a like-for-like build possible on either server.
Where these figures come from. R6725: Dell PowerEdge R6725 Technical Guide (May 2026) (Dell document). SR645 V3: Lenovo ThinkSystem SR645 V3 Server Product Guide (publication date is not printed in the text export; guide contains 'New as of July 2026' notes) (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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