Dell PowerEdge R740 Upgrade Guide: RAM, Storage and CPU

Updated Oct. 7, 2026 · Written from this device's verified specifications

This guide covers memory and storage upgrades for the Dell PowerEdge R740 2U rack server, plus what to check before swapping CPUs. In short, it takes registered ECC DDR4 (RDIMM or LRDIMM) in 24 sockets, and its front drive bays are fixed by the backplane it was built with.

At a glance

  • 24 DDR4 sockets; registered ECC RDIMM or LRDIMM only (no UDIMM or SO-DIMM), and the two types can't be mixed.
  • Up to 3 TB with two CPUs; one CPU supports half that (1.5 TB).
  • 2933 MT/s needs 2nd Gen Xeon Scalable CPUs; LRDIMMs run at 2666 MT/s.
  • Front bays are 8 x 3.5" or up to 16 x 2.5" (SATA/SAS) and the count can't be added later.
  • The optional BOSS card takes two M.2 SATA SSDs for boot only; it is not NVMe.
DIMM sockets24 × DDR4 DIMM · up to 3.072 TB total · 2933 MT/s · registered (RDIMM) · ECC
Front 3.5" hot-swap bays8 × HDD / SSD 3.5" / 2.5" (SATA / SAS)
Front 2.5" hot-swap bays16 × HDD / SSD 2.5" (SATA / SAS)
BOSS M.2 boot card2 × SSD M.2 2280 (SATA) · up to 480 GB
IDSDM microSD slots3 × Flash card microSD (Proprietary) · up to 64 GB
24 × DIMM · DDR4up to 3 TB totalFront 3.5" hot-swap bays8 × HDD / SSD 3.5" / 2.5" (SATA / SAS)Front 2.5" hot-swap bays16 × HDD / SSD 2.5" (SATA / SAS)BOSS M.2 boot card2 × SSD M.2 2280 (SATA) · up to 480 GBIDSDM microSD slots3 × Flash card microSD (Proprietary) · up to 64 GB
Schematic of the upgradeable slots (not to scale). Check the owner's manual for their exact positions.

Lifecycle and support

No longer sold new. Supported until Dec. 31, 2028 (estimate).

2023202420252026202720282029TodayEnd of sale · Oct. 31, 2023EOSL · Dec. 31, 2028
Filled dots: dates published by the manufacturer. Hollow dots: estimates from third-party sources.
MilestoneDateSource
End of sale
No longer sold new by the manufacturer (Dell calls this 'End of Life', Lenovo 'Withdrawn').		 Oct. 31, 2023 Estimate Estimate
Third-party date from icd3s.com; Dell publishes no model-level date and one source disputes it
End of standard support (EOSL)
Standard warranty and support contracts can no longer be renewed.		 Dec. 31, 2028 Estimate Estimate
Third-party end of support (EOSL) date from icd3s.com; unconfirmed by Dell

Dates not listed haven't been published by the manufacturer or a reliable third party.

RAM: 24 DDR4 sockets, registered ECC only

The R740 has 24 full-size 288-pin DDR4 sockets and no soldered memory, so all capacity is in the DIMMs. It accepts registered ECC RDIMMs or LRDIMMs. RDIMMs and LRDIMMs can't be mixed in the same system, and consumer UDIMMs and laptop SO-DIMMs won't work. NVDIMM-N and Intel Optane DC persistent memory are also supported, with restrictions.

The largest module is a 128 GB octa-rank LRDIMM; the largest RDIMM is 64 GB. With two CPUs and 24 x 128 GB LRDIMMs you reach 3 TB. With one CPU, Dell's limits are half of that: 1.5 TB with 128 GB LRDIMMs, or 768 GB with 64 GB RDIMMs. Check Dell's memory population guidelines for how the sockets are split between CPUs.

Speed depends on the CPU generation, DIMM type and DIMMs per channel, so 2933 MT/s is the best case. 16, 32 and 64 GB dual-rank RDIMMs run at 2933 MT/s with one DIMM per channel and 2666 MT/s with two per channel, but only with 2nd Gen Xeon Scalable CPUs. First-generation CPUs top out at 2666 MT/s. 8 GB single-rank RDIMMs and 64 GB and 128 GB LRDIMMs run at 2666 MT/s.

NVDIMM-N modules are 16 GB, up to 12 (192 GB), and need two CPUs; 8 GB RDIMMs must not be mixed with them. Optane DC persistent memory comes in 128, 256 and 512 GB modules, up to 12, and Dell lists it under 2nd Gen Xeon processors. Older documentation lists only RDIMM, LRDIMM and NVDIMM-N, so check which CPU generation your unit has.

Buying tips

  • Buy registered ECC DDR4 labelled RDIMM or LRDIMM, and don't mix the two types.
  • Check your CPU generation first; 1st Gen CPUs won't give you 2933 MT/s even with faster DIMMs.
  • For top speed, choose dual-rank RDIMMs and leave one DIMM per channel; filling more sockets drops them to 2666 MT/s.
  • Confirm whether your server has one or two CPUs before planning more than half the maximum capacity.

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Storage: front hot-swap bays, BOSS card and IDSDM

The front bays come in two layouts: 8 x 3.5" or up to 16 x 2.5", all SATA or SAS, HDD or SSD. The 8-drive chassis can also take 2.5" drives. The bay count and drive type depend on the backplane the server was built with and can't be added later. Drives must be in hot-swap carriers, and a PERC or HBA controller is needed. Dell's documents we checked don't state a drive thickness limit for the 2.5" bays. The R740 has no rear or mid-chassis drive bays; those belong to the R740xd.

NVMe is unclear. Dell's technical guide mentions NVMe in a table shared with the R740xd, and the retrieved text doesn't say how many NVMe bays an R740 can have. If you want NVMe drives, confirm the backplane option before buying.

For boot storage, the optional BOSS card holds two M.2 SATA SSDs (240 or 480 GB) with hardware RAID. It is boot-only and SATA, not NVMe. Dell doesn't state the M.2 length; 80 mm (2280) is typical, so verify before buying. The card is low-profile only and sold separately.

The optional IDSDM with vFlash is a Dell-proprietary module at the rear. It takes three microSD cards: two for IDSDM (16, 32 or 64 GB) and one 16 GB card for vFlash. It is also sold separately.

Buying tips

  • Check which backplane you have (8 x 3.5" or 16 x 2.5") before choosing drives; you can't add bays later.
  • Make sure drives come with hot-swap carriers.
  • Buy SATA or SAS drives, and confirm a PERC or HBA is fitted.
  • Treat the BOSS card as a boot drive only, and check that a used server includes it.
  • Don't assume NVMe works until you've confirmed the backplane option.
  • Third-party drives may behave differently from Dell-branded ones, for example with firmware or fan-speed behaviour.

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How to upgrade

Before you start

  • Confirm your CPU generation (1st or 2nd Gen Xeon Scalable) and whether one or two CPUs are fitted.
  • Confirm your front-bay layout (8 x 3.5" or 16 x 2.5") and which of BOSS, IDSDM and PERC or HBA are installed.
  • Back up your data and note your current RAID configuration.
  • Update the BIOS and firmware if Dell recommends it for the part you are adding; check the owner's manual and Dell's support pages.
  • Have the owner's manual open for exact disassembly steps, plus an anti-static wrist strap.

Steps

  1. Back up and prepare
    Back up all important data and note your RAID setup. If you are only swapping a hot-swap drive, still back up first.
  2. Power off and unplug
    Shut the server down properly, then disconnect all power cords and cables. Hot-swap drives can be handled without opening the case, but follow the owner's manual for that procedure.
  3. Ground yourself
    Wear an anti-static strap or touch bare metal on the chassis before handling memory, CPUs or cards. Hold parts by their edges.
  4. Open the server
    For memory, CPU or card work, remove the server from the rack if needed and open the cover as described in the owner's manual.
  5. Install the part
    Fit memory in the sockets Dell's population guidelines call for, and seat drives in their hot-swap carriers. Add a BOSS or IDSDM module in its designated slot. For a CPU change, follow the owner's manual exactly.
  6. Close and reconnect
    Refit the cover, rack the server, and reconnect cables and power.
  7. Check that the system sees the part
    Power on and confirm the memory size, drives or CPU appear in the BIOS or system setup and in the management interface. Set up RAID if needed, and apply any firmware updates.

Good to know

  • Dell's documents we checked don't list which CPU models the R740 supports, their power limits or the socket type. Check Dell's manual for your exact configuration before buying a CPU. They do show up to two 2nd Gen Xeon Scalable processors, and 1st Gen CPUs limit memory to 2666 MT/s.
  • Dell's spec sheets disagree on maximum storage: the current one says 122.88 TB (2.5") and 128 TB (3.5"), while an older one says 61 TB and 96 TB, because larger drives were added over time.
  • Older Dell documents list fewer memory options (no Optane persistent memory) and fewer storage controllers than the newer ones, so the exact options depend on when your unit was built.
  • Drive thickness limits and M.2 length aren't stated in Dell's documents we checked; verify before buying.
  • Don't confuse the R740 with the R740xd or R740xd2, which have different bay layouts.

Frequently asked questions

How much RAM can the Dell PowerEdge R740 take?

Up to 3 TB with two CPUs, using 24 x 128 GB LRDIMMs. With one CPU the limit is half: 1.5 TB with 128 GB LRDIMMs, or 768 GB with 64 GB RDIMMs.

What type of RAM does the R740 use?

Registered ECC DDR4 in full-size 288-pin DIMMs, either RDIMM or LRDIMM. Consumer UDIMMs and SO-DIMMs don't work, and RDIMMs and LRDIMMs can't be mixed.

How fast can the R740's memory run?

Up to 2933 MT/s, but only with 2nd Gen Xeon Scalable CPUs and dual-rank RDIMMs at one DIMM per channel. Two DIMMs per channel, LRDIMMs and 1st Gen CPUs give 2666 MT/s.

Does the R740 support NVMe SSDs?

We couldn't confirm how many NVMe bays an R740 can have. Dell lists NVMe SSDs in a guide shared with the R740xd, so check the backplane option on the exact server before buying.

Can I add more drive bays to an R740?

No. The bay count and drive type depend on the chassis and backplane it was built with: 8 x 3.5" or up to 16 x 2.5". Drives need hot-swap carriers and a PERC or HBA controller.

Can I use an M.2 SSD in the R740?

Only through the optional BOSS card, which takes two M.2 SATA SSDs (240 or 480 GB) for boot use. It is not NVMe, and it is sold separately.

Official documents and references

This guide was written with AI assistance from the compatibility data PartsPrices verified against the manufacturer's documents. Always check your exact model and the owner's manual before buying or opening your computer.