Dell PowerEdge R640 vs R650: Which 1U Rack Server Is Right for You?
The Dell PowerEdge R640 and R650 are two of the most popular 1U rack servers in enterprise data centers worldwide. The R640 (14th generation) dominated from 2017 to 2021, while the R650 (15th generation) took over as Dell’s mainstream 1U platform. If you are building out infrastructure, refreshing aging hardware, or expanding capacity, understanding the differences between these two servers is critical to making the right investment.
This guide provides a detailed, spec-by-spec comparison to help you decide whether a refurbished R640 or a new/refurbished R650 is the better fit for your workload and budget.
Specifications Comparison: R640 vs R650
| Specification | PowerEdge R640 (14th Gen) | PowerEdge R650 (15th Gen) |
|---|---|---|
| CPU Family | Intel Xeon Scalable 1st/2nd Gen | Intel Xeon Scalable 3rd Gen (Ice Lake) |
| Max Processors | 2 | 2 |
| Max Cores (2P) | 56 (2x 28-core) | 80 (2x 40-core) |
| Memory Type | DDR4 ECC RDIMM/LRDIMM | DDR4 ECC RDIMM/LRDIMM |
| Max Memory Speed | 2666 MHz | 3200 MHz |
| DIMM Slots | 24 | 16 |
| Max RAM | 3TB (24x 128GB LRDIMM) | 2TB (16x 128GB LRDIMM) |
| PCIe Generation | PCIe 3.0 | PCIe 4.0 |
| PCIe Slots | Up to 3 | Up to 3 |
| Drive Bays (SFF) | Up to 10x 2.5″ | Up to 10x 2.5″ |
| NVMe Support | Up to 10 (via PCIe 3.0) | Up to 10 (via PCIe 4.0) |
| Management | iDRAC 9 | iDRAC 9 |
| Max Network Speed | 25GbE (OCP) | 25GbE (OCP 3.0) |
| Power Supply | 750W / 1100W | 600W / 800W / 1100W / 1400W |
| Dell Support Status | End of Sale (EOSL ~2027) | Active Support |
CPU Performance: Cascade Lake vs Ice Lake
The most significant upgrade from R640 to R650 is the processor platform. The R640 supports Intel Xeon Scalable 1st Gen (Skylake-SP) and 2nd Gen (Cascade Lake-SP), while the R650 moves to 3rd Gen (Ice Lake-SP).
Key performance gains in the R650:
- Up to 43% more cores per socket (40 vs 28)
- Higher memory bandwidth: DDR4-3200 vs DDR4-2666 (20% improvement)
- PCIe 4.0: Double the I/O bandwidth per lane compared to PCIe 3.0
- Improved IPC: Ice Lake delivers 15-20% better instructions-per-clock
- Built-in AI acceleration: DL Boost with VNNI for inference workloads
For compute-intensive workloads — virtualization at scale, databases, analytics — the R650 delivers meaningfully more performance per rack unit.
Memory: More Slots vs Faster Speed
This is where the comparison gets interesting. The R640 has 24 DIMM slots supporting up to 3TB, while the R650 has only 16 DIMM slots supporting up to 2TB.
If your workload demands maximum memory capacity in a 1U form factor (databases, in-memory analytics, large VDI deployments), the R640 actually has an advantage. However, the R650 compensates with faster DDR4-3200 memory, delivering higher bandwidth per module.
For most workloads, 2TB in a 1U server is more than sufficient. But if you need 2TB+ in 1U, the R640 (or R740xd in 2U) remains the better option.
Storage and I/O: PCIe 4.0 Changes the Game
The R650’s move to PCIe 4.0 has a cascading impact on storage performance:
- NVMe drives: PCIe 4.0 NVMe SSDs deliver up to 7,000 MB/s sequential read vs 3,500 MB/s on PCIe 3.0
- Network cards: PCIe 4.0 enables 100GbE without bottlenecking
- GPU/accelerator support: Full bandwidth for inference cards
If you are running all-NVMe storage or high-speed networking, the R650’s PCIe 4.0 support alone justifies the upgrade.
When the Refurbished R640 Makes More Sense
The Dell PowerEdge R640 remains an excellent server for many use cases. Here is when it is the smarter buy:
- Budget-constrained deployments: Refurbished R640 systems start from approximately $1,800, compared to $3,000+ for the R650
- Maximum memory density: 24 DIMM slots vs 16 — critical for memory-heavy workloads
- SAS/SATA storage: If you are using spinning disks or SATA SSDs, PCIe 3.0 is not a bottleneck
- Established environments: If your data center already runs R640s, adding more of the same simplifies management, spare parts, and training
- Development and test labs: Enterprise-grade hardware at a fraction of the cost
- DR/backup sites: Secondary sites where peak performance is not required
At ICD, our refurbished R640 systems come fully tested with a warranty, configured to your specifications. Browse available configurations on our R640 product page.
When You Should Choose the R650
The Dell PowerEdge R650 is the right choice when:
- Performance per watt matters: Ice Lake is more power-efficient per core
- NVMe-heavy storage: PCIe 4.0 doubles your storage throughput ceiling
- Long lifecycle planning: Active Dell support means patches, firmware, and warranty coverage for years to come
- High-speed networking: 100GbE and beyond without PCIe bottlenecks
- Compliance requirements: Some regulated environments require hardware under active vendor support
- New deployments: If you are building from scratch, future-proofing with the newer generation makes sense
Cost Comparison
| Configuration | R640 (Refurbished) | R650 (Refurbished/New) |
|---|---|---|
| Base (2P, 64GB, 2x 480GB SSD) | ~$1,800 | ~$3,000 |
| Mid (2P, 256GB, 4x 960GB SSD) | ~$2,800 | ~$4,500 |
| High (2P, 512GB, 8x 1.92TB NVMe) | ~$5,500 | ~$8,500 |
The R640 typically offers 35% to 45% savings over equivalent R650 configurations. For budget-sensitive deployments where raw performance is not the primary concern, the savings are substantial.
Parts Availability and Long-Term Support
Both the R640 and R650 use widely available components. At ICD, we maintain extensive inventory for both platforms:
- CPUs: Full range of Xeon Scalable processors for both generations
- Memory: DDR4 ECC RDIMM and LRDIMM in all capacities (see our memory catalog)
- Storage: SAS, SATA, and NVMe drives compatible with both platforms
- Network cards: 10GbE, 25GbE, and 100GbE options
- Power supplies, fans, risers, bezels: All service parts available
For R640 systems approaching Dell EOSL, ICD offers third-party maintenance (TPM) and SPaaS (Server Parts as a Service) to keep your hardware running with guaranteed parts availability and SLA-backed support. Contact us for a custom support plan.
The Verdict
There is no universal right answer. The R640 wins on value, memory capacity, and cost efficiency. The R650 wins on raw performance, I/O bandwidth, and future-proofing.
For most enterprises doing a data center refresh in 2026, we recommend a mixed approach: R650s for performance-critical workloads (databases, primary virtualization hosts) and refurbished R640s for secondary workloads, DR sites, and capacity expansion.
Need help choosing? Use our Parts Finder to compare configurations, or contact our sales team for a personalized recommendation based on your workload requirements.
Frequently Asked Questions
Can I upgrade a Dell R640 to R650 specifications?
No. The R640 and R650 use different motherboard architectures and CPU sockets (LGA 3647 vs LGA 4189). You cannot upgrade the processor platform. However, you can maximize your R640 by upgrading memory, storage, and network cards to the highest supported specifications.
Do both the R640 and R650 use DDR4 memory?
Yes. Both servers use DDR4 ECC memory. The R640 supports up to DDR4-2666, while the R650 supports DDR4-3200. The R640 has 24 DIMM slots (max 3TB), and the R650 has 16 DIMM slots (max 2TB). DDR4-3200 modules are backward compatible with the R640 at 2666 MHz speeds.
Is the Dell R640 still a good server in 2026?
Absolutely. The R640 with dual Xeon Gold or Platinum processors and ample DDR4 RAM remains a capable platform for virtualization, web hosting, databases, and general enterprise workloads. Its 24 DIMM slots give it a memory capacity advantage over the newer R650.
What is the price difference between a refurbished R640 and R650?
Refurbished R640 systems typically start around $1,800 for a base dual-processor configuration, while comparable R650 systems start around $3,000. The R640 offers approximately 35% to 45% savings across similar configurations.
Does ICD sell both Dell R640 and R650 servers?
Yes. ICD offers both refurbished R640 and R650 systems, as well as individual components (CPUs, memory, drives, network cards, power supplies) for both platforms. All refurbished systems are fully tested and include a warranty. Browse our inventory on the R640 and R650 product pages.