Dell EMC PowerEdge R840 Server ReviewNovember 12, 2019
The Dell EMC PowerEdge R840 server (SHOP HERE) is undeniably the perfect fit for data-intensive applications, data analytics, artificial intelligence, machine learning, and a multitude of other high performance computing applications. This flagship server has four-sockets in a 2U platform supporting nearly the same storage at 26 bays and the same memory at 6TB as the R940 and R940xa servers.
By the numbers, the R840 offers 62% more storage, twice the memory capacity, and a 27% increase in CPU cores, and a 3.5X faster response time compared to its predecessor, the R830. Aside from the 4U height on the R940xa server, the R940xa and the R840 have a very similar spec. For example, they both use the same motherboard. Both support SAS, SATA, and NVMe storage but you get up to 24 NVMe on the R840. Memory support is the same at 6TB Intel Optane memory modules, which are also supported, will give you a little over 12TB of memory!
In addition, there are also four processors which all reside on the same circuit board with no processor expansion module, or PEM. The R840 is also designed to handle GPUs or Field Programmable Gate Arrays, but only half as many compared to the R940xa, but you do get more NVMe storage—like 6X more!
The Dell EMC R840 has a cyber-resistant architecture and several levels of security, plus automated management features designed to protect your system and data through Dell OpenManage. An optional LCD bezel with lock provides system status and security for your upfront drives, very useful in a data center for at-a-glance status.
Furthermore, the right server ear supports several ports including a VGA port, two USB ports, and a micro USB port to access iDRAC for diagnostics or system status. With iDRAC9 you get an improved HTML5 user interface providing a wealth of information and security protocols, including secure erase and system lockdown.
An information button on the left server ear provides server health status with a QuickSync II button just below that. The QuickSync II button allows you to temporarily pair a smartphone or tablet outfitted with Dell’s OpenManage mobile app for system status and diagnostics. The system comes standard with OpenManage Enterprise, which will support several generations of Dell servers and third-party appliances.
Once you remove the bezel, you’ll see either 24x or 8x vertical drive bays, like on our chassis, which is an entry-level system. The R940xa supports only four NVMe drives up front, in certain configurations. However, the Dell PowerEdge R840 universal drive bays can be loaded with up to 24 x SAS, SATA or NVMe drives. You can install up to 24 direct-attached NVMe drives for reduced latency and a maximum of 153TB of storage. You can also go for a hybrid configuration with a mix of SAS and SATA, plus up to 12 NVMe drives for 184TB of storage.
However, this chassis will only support eight drives up front with the currently installed backplane for a maximum capacity of 61TB. In other words, you will need the 24-bay universal backplane, the SAS expander board, and several ancillary cables to accept 24 drives up front. SATA and NVMe PCIe drives are handled natively, but for SAS or more control over your storage, you can choose from a range of PERC controllers.
On the back of the chassis you can install two more 2.5-inch SAS or SATA drives using an optional PCIe-mounted drive cage. As a result, the drive cage will take the place of riser 2 and you won’t be able to install any GPUs, but what you will get is up to 15TB more of SAS or SATA storage accessible from the back of the system. You have an option for up to 6 PCIe 3.0 slots using two risers with two PCIe slots in each riser and two more (PCIe 3 and 4) on the system board. Although if you install the rear drive cage, your PCIe slots will be reduced.
A slot for a network daughter card is located in the lower left of the chassis and just like on the R940xa there are a lot of options for connection speeds and ports. Not to mention additional network controllers through the PCIe slots, of which again there are multiple options. Power is provided by dual redundant 1600W PSUs on this system, but there are more options available including a platinum 2400W PSU.
Furthermore, the layout inside the case is also very similar to the R940xa. There’s a black plastic shroud with two tiers of cooling channels. One for the processors and memory, and the other for cooling the PCIe cards, and in this case GPUs. The two PCIe risers at the back of the chassis are for expansion cards, and at the front behind the HD backplane is a removable cage for six high-capacity hot-swap fans. Once those are removed, you see the same motherboard as the R940xa. Certainly, gone is the processor expansion module that supported the third and fourth processors plus associated memory slots like on the previous generation R830.
Each processor has a complement of 6 memory module slots to either side for a total of 12 per processor and 48 active memory module slots with all four processors. You can install either Gen 1 or Gen 2 Intel Xeon Scalable processors from the Gold or Platinum families featuring three ultra-path Interconnects for faster data transfers. However, you will need an “M” suffix processor if you plan on installing the maximum memory of up to 6TB. In addition, memory supported on the system includes registered, load reduced and up to 12 NVDIMM modules. Using Gen1 processors will support memory speeds of up to 2666MT/s, but with Gen 2 processors that number bumps up to 2933MT/s.
You can use one of the PCIe ports for an optional boot optimized storage subsystem or BOSS. The BOSS will support one or two 6Gb/s M.2 SATA drives and features optional hardware RAID when outfitted with two M.2s for redundancy. If you need to accelerate compute, then you have the option of installing either two full-height, full-length GPUs from Nvidia, or two Field-Programmable Gate Arrays. The latter are used for very specific applications and are programmable.
With four processors, Dell EMC’s PowerEdge R840 server delivers some very impressive performance for ultra-fast, time-critical applications like processing for in-memory database, high frequency trading, machine learning and artificial intelligence. It supports the most GPUs or FPGAs of any 2U system. Surprisingly, for a 2U system, there is plenty of room to scale.