Lenovo ThinkSystem SR645
The ThinkSystem SR645 was Lenovo's high-core-density 1U dual-socket rack server built on AMD EPYC 7002 (Rome) and 7003 (Milan) Series processors. With up to 128 physical x86 cores in a 1U chassis, 32 DDR4-3200 DIMM slots, and 128 lanes of native PCIe 4.0 connectivity, it targeted dense virtualization clusters, electronic design automation (EDA), in-memory analytics, and container infrastructure. The chassis accommodated up to 12 direct-attach NVMe solid-state drives without requiring PCIe switches. When acquiring refurbished units, buyers should confirm that performance copper heatsinks and high-CFM dual-rotor fans are installed, verify XClarity license keys, and ensure dual 1100W or 1800W power supplies are fitted for 280W EPYC CPUs.
Also written as: ThinkSystem SR645, SR645 Gen1, 7D2X, 7D2Y
Specifications
| Brand | Lenovo |
|---|---|
| Family | ThinkSystem SR |
| Form factor | 1U rack |
| Released | May 2020 |
| End of sale | Mar 2024 |
| Cpu sockets | 2 |
| Cpu platform | Dual AMD EPYC 7002 (Rome) and 7003 (Milan) Series processors up to 64 cores per socket and 280W TDP |
| Memory slots | 32 |
| Memory type | DDR4-3200 RDIMM / 3DS RDIMM |
| Memory max (GB) | 8,192 |
| Drive bays | Up to 12x 2.5-inch SFF hot-swap bays (including up to 12 direct NVMe bays) or 4x 3.5-inch LFF bays |
| Pcie slots | Up to 3 PCIe 4.0 slots plus 1 OCP 3.0 slot |
| Network onboard | OCP 3.0 slot plus dedicated 1GbE XClarity management port |
| Power supply | Dual redundant 750W / 1100W / 1800W AC 80 PLUS Platinum or Titanium PSUs |
Generations
- Next generation: Lenovo ThinkSystem SR645 V3
Reference prices (last 14 days, updated 2026-10-27)
Refurbished: USD 3,950 (1 sighting, Oct 2026)
Used: USD 2,800 (1 sighting, Oct 2026)
All sightings
| Seller | Condition | Price | Note | Seen |
|---|---|---|---|---|
| ebay.com | used | USD 2,800 | 2x AMD EPYC 7542 32-core, 128GB DDR4-3200, 8-bay chassis, dual 1100W PSUs | 2026-10-27 |
| serversupply.com | refurbished | USD 3,950 | 2x AMD EPYC 7702 64-core, 256GB RAM, refurbished with warranty | 2026-10-27 |
Prices seen on public listings on the dates shown, before tax and shipping. Not an offer.
Compatible parts
Memory
- 4X77A08632 Lenovo ThinkSystem 16GB TruDDR4 3200MHz (1Rx4 1.2V) RDIMM
- 4X77A08634 Lenovo ThinkSystem 64GB TruDDR4 3200MHz (2Rx4 1.2V) RDIMM
- 4X77A83756 ThinkSystem 32GB TruDDR4 3200MHz (2Rx4 1.2V) RDIMM
RAID controllers
- 4Y37A09730 Lenovo ThinkSystem RAID 940-16i 8GB Flash PCIe Gen4 12Gb Adapter
SSDs
- 4XB7A17128 ThinkSystem 2.5" S4620 3.84TB Mixed Use SATA 6Gb HS SSD
Equivalent models from other brands
- Dell Poweredge R6525
- HPE Proliant DL365 Gen10 Plus
Buying a used SR645: what to check
Check XClarity Controller license level, verify processor heatsinks match installed AMD EPYC TDP ratings (280W models require performance heatsinks), inspect PCIe 4.0 risers, and confirm OCP 3.0 mezzanine adapter presence.
FAQ
What processors run in the ThinkSystem SR645?
It supports 2nd Gen (Rome 7002) and 3rd Gen (Milan 7003) AMD EPYC processors up to 64 cores per socket.
How many NVMe drives can be connected directly to the SR645?
The SR645 can accommodate up to 12 direct-attach 2.5-inch NVMe PCIe 4.0 SSDs in its 1U chassis.
What server succeeded the SR645?
The ThinkSystem SR645 V3 succeeded it, featuring 4th/5th Gen AMD EPYC 9004/9005 processors and DDR5 memory.
Buying or selling SR645?
New, refurbished or used. Tell us the quantity and condition and we connect you with a vetted reseller in your region, usually within one working day.
Sources
- Lenovo ThinkSystem SR645 Server Product Guide, checked 2026-10-27