Dell PowerEdge R640 Servers

Chassis options

The R640 was built in three front-bay configurations. The chassis cannot be converted from one to another after purchase, so choose by how many drives you need and what type.

All three variants support an optional BOSS card with two M.2 SATA SSDs for a mirrored boot volume, keeping the front bays free for data.

Processors

The R640 accepts first-generation (Skylake-SP, 2017) and second-generation (Cascade Lake, 2019) Intel Xeon Scalable processors in two LGA3647 sockets. Second-generation CPUs need a BIOS at 2.x or later and unlock 2933 MT/s memory. Both CPUs in a system must be identical. The list below covers the SKUs most commonly found in refurbished R640 units; the platform supports the full range up to 28 cores and 205 W.

Second-generation Xeon Scalable (Cascade Lake)

First-generation Xeon Scalable (Skylake-SP)

Silver and Gold 5xxx processors cap memory at 2400 or 2666 MT/s regardless of the DIMMs fitted. If memory bandwidth matters to your workload, a Gold 6xxx or Platinum with second-generation silicon is the difference between 2400 and 2933 MT/s on the same board.

Memory

Twenty-four DDR4 DIMM slots, twelve per processor across six channels. Registered (RDIMM) and load-reduced (LRDIMM) modules are supported; they cannot be mixed in the same system. With one CPU installed, only the twelve slots on that side are usable.

For best performance populate all six channels per CPU in matched sets: 6, 12 or 24 DIMMs in total for a dual-CPU system. A single DIMM per CPU works but runs at a fraction of the available bandwidth. Memory runs at the lower of the DIMM rating and the CPU limit, so 2933 MT/s modules on a Silver 4214 run at 2400 MT/s.

Storage and RAID

Drive support depends on the backplane fitted at the factory. All backplanes are hot-plug. The controller options are:

Supported drive types are 12 Gb/s SAS and 6 Gb/s SATA in both hard disk and SSD form, plus U.2 NVMe on the 10-bay NVMe backplanes. Drives need the correct Dell 14th generation caddy: the 2.5" and 3.5" carriers are not interchangeable with 11th or 12th generation units.

Networking and expansion

Onboard networking is provided by a Network Daughter Card (NDC) that slots into a dedicated connector rather than a PCIe slot. Common options:

• Broadcom 5720 quad-port 1 GbE (the base configuration)
• Intel X550 or Broadcom 57416 dual-port 10 GbE BASE-T plus dual-port 1 GbE
• Intel X710 quad-port 10 GbE SFP+
• Mellanox ConnectX-4 Lx dual-port 25 GbE SFP28

Beyond the NDC, the R640 offers up to three PCIe Gen3 slots depending on the riser configuration, typically two x16 and one x8 in low-profile form. That is enough for an additional NIC, a Fibre Channel HBA and a single-width accelerator such as the NVIDIA T4. Full-height or double-width GPUs need the 2U R740.

Power supplies

Two hot-plug redundant power supply bays, configured 1+1. Options are 495 W, 750 W, 1100 W and 1600 W, all 80 PLUS Platinum or Titanium. A dual-CPU system with a full memory load and a PERC generally sits within the 750 W envelope; specify 1100 W when adding NVMe drives or an accelerator. Both supplies in a system should be the same rating.

Management

Every R640 includes iDRAC9 with a dedicated management port. The Express licence covers remote power, health monitoring and basic alerts; the Enterprise licence adds the virtual console, virtual media, remote firmware updates through the Lifecycle Controller and the full Redfish API, which is what most buyers actually want for a server in a rack they do not visit. Enterprise licences can be added to any unit. The R640 also supports OpenManage Enterprise for fleet management.

Physical specification

Supported operating systems

Windows Server 2016, 2019 and 2022; Red Hat Enterprise Linux 7 and 8; SUSE Linux Enterprise Server 12 and 15; Ubuntu Server LTS releases; VMware ESXi 6.5, 6.7 and 7.0; Citrix Hypervisor; and Proxmox VE, which is unsupported by Dell but widely deployed on this platform. Windows Server 2025 and ESXi 8 are outside Dell's support matrix for the R640 but run on it. Confirm your hypervisor's hardware compatibility list before buying if you need vendor support.

Buying a refurbished R640 from ServerDove

Every unit we sell has been through full hardware diagnostics and a burn-in run: memory tested across every installed DIMM, controller and drive health verified, both power supplies load-tested, and the iDRAC reset and confirmed reachable. BIOS is returned to defaults and the firmware brought to a stable release. Units carry a six-month warranty and are held in Doha, so a replacement part is a short drive away rather than a shipment from overseas.

Because the R640 is now past Dell's mainstream support window, we are also the practical route to keeping one in service: we stock the caddies, DIMMs, PERC cards, NDCs, power supplies and rail kits that fit it, and our hardware support plans cover units bought elsewhere as well as our own.

If you need a specific configuration that is not listed, tell us the CPU, memory and drive layout you want and we will quote a build from stock. Custom configurations are usually ready within two working days.