Dell PowerEdge R660 Servers – new and refurbished

The Dell PowerEdge R660 is a dual-processor 1U rack server featuring Intel Xeon Scalable 4th and 5th generation processors, DDR5 memory, NVMe drives, and iDRAC9 remote management. It accommodates up to 32 RAM modules and up to 10 2.5" drives, so a single unit in the rack can support ERP, an SQL database, or a virtual environment for several, and with lighter services even a dozen or more machines. Below, we show how to configure it to avoid overspending and running out of capacity within a year.

The R660 is a representative of Dell 16th generation servers in a 1U chassis, a flat „pizza box” occupying one unit in the rack. It has two processor sockets, 32 memory slots, and redundant power supply, so in the space of one basic server you get a fully capable production node. If every U in the rack counts, and the company runs ERP, a database, or several virtual machines, rack servers of this class are a natural choice. For companies replacing 5–7-year-old R640 or R630 units, this is a straightforward successor: the same chassis philosophy, but with DDR5, faster NVMe, and newer processors. It is worth noting that 1U is a trade-off: less room for 3.5" drives and large expansion cards than in a 2U chassis. In a small office without a rack, consider tower servers instead.

With servers for Microsoft SQL Server, performance is determined by drive speed, the amount of RAM, and processor clock speed, and only then by core count. A database whose active data fits in memory does not wait for the disk, which is why 128–256 GB RAM is a reasonable starting point for a typical ERP database in a small to medium-sized business. SQL licenses are counted per core, so a processor with fewer cores and higher clock speed can be less expensive in total cost than „more cores just in case”. If the environment is based on servers for Comarch Optima or servers for enova365, a single Xeon Silver or Gold processor usually suffices, leaving the second socket available for future expansion. Large SAP installations already require two processors and more memory. A sample layout for a database of approximately 500 GB (an example, not a standard) looks as follows.

• 256 GB RAM, so that active data fits in memory.
• NVMe drives in RAID 10 for the database and logs.
• A separate volume for backups.

More information in the database servers category.

Let us calculate this with an example. Assumptions:

• 2 processors with 16 cores each, meaning 32 physical cores,
• 20 machines with 4 vCPUs and 16 GB RAM each, totaling 80 vCPUs (approximately 2.5 vCPUs per core, typical for lightweight services),
• 320 GB RAM for the machines, and with the hypervisor and headroom for peaks, 512 GB RAM.

Such a setup can support a domain controller, a file server, ERP, web services, and a test environment. For heavy databases, the ratio should be reduced to 1:1. The R660 works with VMware, Hyper-V, and Proxmox, and two or three servers plus a disk array form an HA cluster in which the failure of a single node does not bring the company to a halt. On VMware servers, memory runs out faster than cores, so leave DIMM slots available.

Memory. Each processor has 8 DDR5 channels, and the motherboard provides 16 slots per processor. Populate channels evenly, for example 16 modules of 32 GB each rather than 8 modules of 64 GB, as this delivers higher throughput at the same total capacity. 4th generation memory operates at up to 4800 MT/s, 5th generation at up to 5600 MT/s; check the RDIMM RAM offering and match it to Intel Xeon Scalable 4th generation processors.

Drives and RAID. NVMe drives are many times faster than SAS and SATA for small random reads, which is exactly how databases and virtual machines operate (the mechanism is described in our article on NVMe drives in servers). The array is managed by Dell RAID controllers, and the choice depends on the drives:

• PERC H755 for SAS and SATA,
• H755N for NVMe,
• H965i in newer configurations.

You can install the operating system on a BOSS-N1 with two M.2 drives in RAID 1, so all 2.5" bays remain available for data. RAID 10 is the recommended choice for databases and virtualization, RAID 5 or 6 for archives. RAID protects against drive failure but is not a backup, as we discuss in the article RAID: data protection or unnecessary expense. Keep backups separately, following the 3-2-1 principle.

The selection comes down to four scenarios.

• Choose the R660 when you want a 1U Intel-based server with DDR5.
• Choose the R650 when the budget is limited, as DDR4 is less expensive and still sufficient for many use cases.
• Choose the R6625 for the best cores-per-dollar ratio in virtualization.
• Choose the R760 when you need more drives or expansion cards.

A full comparison is available in the Dell G16 rack servers category, with additional guidance in the article how to choose a server.

iDRAC9 allows you to access the server remotely and:

• view the console,
• mount a system image,
• check temperatures and drive status,
• power on a shut-down server, without traveling to the data center.

Keep its firmware updated, as vulnerabilities such as the regreSSHion vulnerability in iDRAC affect real machines. The standard OCP 3.0 card allows you to upgrade from 1 GbE to 10 or 25 GbE without replacing the server, and we can match network adapters to your switch. For lighter AI inference, you can add a low-profile graphics card, while heavier workloads require dedicated AI servers. Connect power supplies to two separate circuits; we discuss power management in the article on managing power in the data center.

A new server provides a full lifecycle, while a pre-owned or recertified unit reduces cost while maintaining production-grade specifications. At Hardware Direct, every configuration is tested before shipment, and the warranty included in the offer is 36 months. We describe the differences in the article new vs. recertified server. Build your own configuration in the R660 configurator, and if you are unsure, contact our advisors: we will review your application requirements and recommend the right processor, RAM, and RAID.

Yes, a single Xeon Silver or Gold processor, 128–256 GB RAM, and NVMe drives in RAID 10 are usually sufficient. Match the memory to the size of the database, not to the number of users.

How many virtual machines can I run on the Dell R660?

With 32 cores and 512 GB RAM, approximately 20 lightweight machines with 4 vCPUs and 16 GB RAM each. For heavy databases, the number of machines should be reduced.

Most commonly RAID 10 on NVMe drives: it combines speed with resilience against drive failure. RAID 5 or 6 is better suited for archives. RAID does not replace backup.

The R660 is a 1U server with fewer drive bays and PCIe slots, while the R760 is a 2U server with greater drive capacity and room for expansion cards. The generation and DDR5 memory are the same.

Yes, but only a low-profile card, for example for lighter AI inference. Larger cards require a 2U chassis or a server designed for accelerators.