The Dell PowerEdge R640 is a powerful enterprise server in Dell's 14th generation of servers. There is a total of four different chassis options for the Dell PowerEdge R640 rackmount server. These options are 4 Bay LFF, 8 Bay SFF, 10 Bay SFF, and 10 Bay SFF NVMe. The main differences between each chassis have to do with their bay counts, form factor, and PCIe slots.

4 Bay LFF

The 4 Bay LFF chassis accepts up to four 3.5" SAS or SATA hot swap drives in the backplane. The rear of this chassis has one low-profile PCIe slot and one high-profile PCIe slot. There are no rear drive bays.

8 Bay SFF

The 8 Bay SFF chassis accepts up to eight 2.5" SAS, SATA, or NVMe drives in the backplane. The rear of the chassis has a total of three low-profile PCIe slots with no rear drive bays.

10 Bay SFF

The 10 Bay SFF chassis accepts up to ten 2.5" SAS, SATA, or NVMe drives in the backplane. There are two rear configurations that are possible with this chassis. The first one consists of three low-profile PCIe slots. The second one consists of one low-profile PCIe slot and two rear drive bays.

The Dell PowerEdge R640 server can accept up to 1st Generation and 2nd Generation Intel Xeon Scalable processors. Total of 56 cores with a total of 28 cores per processor.

DIMM Slots & Channels

The Dell PowerEdge R640 Server has a total of 24 DIMM slots which makes this system great in terms of scalability. There are 8 total memory channels. Each memory channel consists of 3 DIMM slots.

Memory Types & Module Capacities

This system accepts DDR4 memory. ECC Registered (RDIMMs), Load Reduced (LRDIMMs), and Intel Optane Persistent Memory (PMem) can be used with the R640, but you cannot mix these two types. Capacities of 8GB, 16GB, 32GB, 64GB, and 128GB, 256GB, and 512GB. 128GB is only available with LRDIMMs and 256GB and 512GB are only available with Intel PMem. With Load Reduced and Intel Optane, you can achieve an overall greater RAM capacity.

Max Configurations

With ECC Registered memory, you can achieve a max of 1.5TB with a configuration of 24x64GB modules. With Load Reduced, the max you can achieve is 3TB with a configuration of 24x128GB modules. With Intel Optane alone, 6.14TB can be achieved with 12x512GB modules.

Supported Memory Speeds

The Dell R640 supports memory speeds of 2133MT/s, 2400MT/s, 2666MT/s, 2933MT/s, and 3200MT/s. The processor you have installed will determine the max memory speed that you can use with your system. For example, if your processor supports a max memory speed off 2666MT/s and you install a 2933MT/s module, the module will clock down to 2666MT/s. 2933MT/s is the fastest possible speed for this system.

Supported Drives (2.5")

Supported Drives (3.5")

How Many Power Supplies does the R640 Take?

The PowerEdge R640 server can hold up to two hot-swap power supplies. Hot swap means that power supplies can be install/removed as long as one power supply remains plugged in.

Power Supply Options

There is a total of seven power supply options for the R640. These options are 495W AC Platinum, 750W AC Platinum, 750W Mixed Mode AC Platinum, 750W AC Titanium, 1100W DC Gold, 1100W AC Platinum, and 1600W AC. There are three options that are only available in China only or in China and Japan. 750W Mixed Mode HVDC and 750W Mixed Mode DC Platinum is only available for China. 1100W Mixed Mode HVDC Platinum is available only for China and Japan.

Wattages and Voltages

The available wattages are 495W, 750W, 1100W, and 1600W. If your application is very power intensive, then it is best to pick either a 1100W or 1600W power supply. 495W and 750W are great for lower end applications. For voltages, it is important that you make sure that the unit you have selected is supported by your connection. Not having the correct voltage for your connection can result in your system not powering on.