Dell OptiPlex 3070 SFF Upgrade Guide: RAM, SSD and CPU

Updated Oct. 9, 2026 · Written from this device's verified specifications

This guide covers the three upgrades most owners of the Dell OptiPlex 3070 Small Form Factor ask about: memory, storage and the processor. The short answer: it takes up to 32 GB of DDR4 desktop memory, one M.2 SSD plus one 3.5" or 2.5" drive, and a socketed 8th or 9th Gen Intel CPU up to 65 W.

At a glance

  • RAM: 2 DDR4 UDIMM slots, non-ECC, up to 32 GB total (2 x 16 GB).
  • Storage: one M.2 slot (2230/2280, SATA or NVMe) plus one internal 3.5" or 2.5" bay.
  • CPU: removable 8th/9th Gen Intel Core, Pentium or Celeron up to 65 W; the Core i7-9700 is the top listed part.
  • Update the BIOS before fitting a 9th Gen CPU.
  • No K-series, i9 or 10th Gen processors are listed by Dell.
DIMM slot (DDR4 UDIMM)2 × DDR4 DIMM · up to 32 GB total · 2666 MT/s
M.2 Socket 3 SSD slotSSD M.2 2230 / M.2 2280 (NVMe / SATA)
Internal 3.5" or 2.5" drive bay (one drive total)HDD / SSD 3.5" / 2.5" (SATA)
LGA1151 CPU socket (Intel H370)LGA1151 (8th/9th gen) · Core 8th gen, Core 9th gen · max 65 W
CPU · LGA1151 v2max 65 W2 × DIMM · DDR4up to 32 GB totalM.2 Socket 3 SSD slotSSD M.2 2230 / M.2 2280 (NVMe / SATA)Internal 3.5" or 2.5" drive bay(one drive total)HDD / SSD 3.5" / 2.5" (SATA)
Schematic of the upgradeable slots (not to scale). Check the owner's manual for their exact positions.

Lifecycle and support

A current model: sold new and supported.

201920202021202220232024202520262027Today11 · Release · June 2019
Filled dots: dates published by the manufacturer. Hollow dots: estimates from third-party sources.
MilestoneDate
Release
First available to buy.		 June 2019 Estimate No official launch date found. Inferred from the June 2019 (Rev. A00) date on Dell's service manual and setup/specifications document, so availability was probably around mid-2019.
Source ↗

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

RAM: two DDR4 desktop slots, up to 32 GB

The OptiPlex 3070 SFF has two user-accessible DIMM slots and no soldered memory. It uses full-size DDR4 UDIMMs, not the laptop-style SODIMMs used in the Micro version. Memory must be non-ECC and unbuffered. Dell lists a 4 GB minimum, 16 GB as the largest module and 32 GB (2 x 16 GB) as the total maximum.

Memory speed depends on your processor. Core i5 and i7 models run memory at up to 2666 MT/s, while Celeron, Pentium and Core i3 models run it at 2400 MT/s, even if you fit faster modules.

Dell recommends matched pairs with the same size, speed and technology. Mismatched modules still work, with a slight performance reduction.

Buying tips

  • Buy DDR4 non-ECC unbuffered desktop DIMMs (UDIMM), not SODIMM and not ECC or registered.
  • For the full 32 GB, buy a matched kit of 2 x 16 GB.
  • DDR4-2666 is the fastest speed worth buying; Celeron, Pentium and i3 systems will run it at 2400 MT/s.

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Storage: one M.2 slot and one drive bay

The main SSD slot is an M.2 Socket 3 slot that takes 2230 or 2280 length drives, either SATA or NVMe. Dell also lists support for Intel Optane. Dell's documents disagree on whether the NVMe link is PCIe x2 or x4, so check any NVMe drive's speed claims with that in mind; expect PCIe Gen 3. Dell sold up to 1 TB in this slot, but that is a configuration Dell offered, not a hard limit. The second, smaller M.2 slot is for Wi-Fi and Bluetooth cards and is not for SSDs.

The SFF also has a single internal drive bay that holds either one 3.5" or one 2.5" SATA drive, not both and not two 2.5" drives. Dell offered 3.5" hard drives up to 2 TB, 2.5" hard drives up to 2 TB and 2.5" SSDs up to 1 TB.

Dell sells 2.5" SSDs only as secondary storage alongside an M.2 SSD as the main drive. Whether the PC will boot from a 2.5" SSD on its own isn't confirmed. Dell doesn't document a thickness limit for 2.5" drives.

Buying tips

  • For the simplest upgrade, buy a 2280 or 2230 M.2 SSD for the Socket 3 slot; both SATA and NVMe types are listed.
  • If you want a second drive, a 2.5" SATA SSD or a 3.5" or 2.5" hard drive fits the bay, but only one drive fits there.
  • Don't plan on a 2.5" SSD as your only boot drive until you've confirmed it works on your unit.
  • Don't put an SSD in the Wi-Fi M.2 slot; the PCIe x16 slot is for expansion cards, not storage.

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CPU: 8th and 9th Gen Intel, up to 65 W

The processor is socketed and removable, since Dell's service manual has removal and installation procedures for it. Dell's documents don't name the socket; with the Intel H370 chipset these CPUs use LGA1151 (300-series). Confirm this against the processor section of the service manual before you buy.

Dell lists 8th Gen parts (for example i3-8100, i5-8400 and i5-8500, i7-8700, Pentium Gold G5400 and G5500, Celeron G4900) and 9th Gen parts (Celeron G4930, Pentium G5420, i3-9100 and i3-9300, i5-9400 and i5-9500, i7-9700). The 8th Gen parts are marked as offered offline only. The Core i7-9700 (8 cores, 65 W) is the highest listed, and nothing above 65 W appears. Dell lists no K-series, i9 or 10th Gen parts, so treat those as unsupported.

Update the BIOS before fitting a 9th Gen CPU, particularly if the PC shipped with an 8th Gen one. Dell's documents don't give a minimum BIOS version for each processor. Dell's BIOS page shows 1.7.1 as the latest version, shared with the Micro and Tower models.

The 35 W T-series 8th Gen parts are unclear. Dell's UK table appears to mark them for the Micro only, while the datasheet lists some under Tower and SFF. Check the exact part against Dell's page for your chassis. Dell doesn't state the heatsink's rated power either, so a 65 W part such as the i7-9700 may run warm in this small case and could throttle under sustained load; that is an expectation, not a Dell statement.

Buying tips

  • Buy only a processor on Dell's list for the SFF; stay at 65 W or below.
  • A 9th Gen CPU is a step up from an 8th Gen one, but update the BIOS first.
  • Prefer standard 65 W parts over 35 W T parts, since T-part support in the SFF is unclear.
  • Check which CPU your PC has now; upgrading within the listed families is the safest route.

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How to upgrade

Before you start

  • Check which processor your PC has now, because it sets your memory speed and your CPU upgrade options.
  • Back up your files, and note your BIOS version before changing a CPU.
  • Have the Dell service manual for the 3070 SFF open for exact disassembly steps.
  • Use a clean, well-lit surface and a Phillips screwdriver; keep any screws you remove together.

Steps

  1. Back up your data
    Copy important files to an external drive or cloud storage, especially if you are replacing or cloning a drive.
  2. Update the BIOS if you are changing the CPU
    If you are fitting a 9th Gen processor, update the BIOS first. Dell's BIOS page lists 1.7.1 as the latest. If your BIOS is older than 1.1.3, Dell says to update to 1.3.1 before going to 1.5.0.
  3. Power off and unplug
    Shut the PC down fully, unplug the power cable and any other cables, and hold the power button for a few seconds to drain residual power.
  4. Ground yourself
    Touch bare metal on the case, or use an anti-static wrist strap, before touching any internal part. Handle memory modules and drives by their edges.
  5. Open the case
    Remove the side cover following the owner's or service manual instructions for the SFF, and lay the PC on its side if needed.
  6. Install the new part
    For RAM, fit matched modules into the DIMM slots. For an M.2 SSD, use the Socket 3 slot, not the Wi-Fi slot. For a 3.5" or 2.5" drive, use the single drive bay. For a CPU, follow the service manual's processor removal and installation procedures exactly.
  7. Close the case and reconnect
    Replace the cover, reconnect the cables and power on.
  8. Check that the BIOS sees the part
    Open the BIOS setup at start-up and confirm the new memory size, drive or processor is shown. For a new SSD, you may then need to install or restore an operating system before it appears in Windows.

Good to know

  • Dell's documents don't name the CPU socket. LGA1151 is inferred from the H370 chipset, so confirm it in the service manual before buying a CPU.
  • Dell's manuals disagree on the M.2 slot's PCIe lanes (x2 versus x4); expect Gen 3 speeds either way.
  • Dell's two sources give a different boost clock for the i7-9700 (4.7 GHz versus 4.8 GHz).
  • Dell doesn't document a maximum thickness for 2.5" drives, and booting from a 2.5" SSD alone isn't confirmed.
  • Support for 35 W T-series 8th Gen CPUs in the SFF is unclear; Dell's tables conflict.
  • Dell doesn't state the heatsink's rated power, so a 65 W CPU may run warm in this small case.
  • Dell's listed capacities (for example 1 TB for M.2) are what Dell sold, not confirmed limits.

Frequently asked questions

How much RAM can the Dell OptiPlex 3070 SFF take?

Up to 32 GB, as two 16 GB DDR4 non-ECC UDIMMs. Dell recommends matched pairs of the same size and speed.

What type of RAM does the OptiPlex 3070 SFF use?

Full-size DDR4 desktop memory (UDIMM), non-ECC and unbuffered. SODIMMs, which the Micro version uses, don't apply to the SFF.

Does the OptiPlex 3070 SFF support NVMe SSDs?

Yes. The M.2 Socket 3 slot takes 2230 or 2280 SSDs, either SATA or NVMe. Dell's documents disagree on whether it is x2 or x4 lanes; expect PCIe Gen 3 speeds.

Can I fit both an M.2 SSD and another drive?

Yes. You can use the M.2 slot plus the single internal bay for one 3.5" or 2.5" drive. The bay holds only one drive in total.

What is the fastest CPU the OptiPlex 3070 SFF supports?

The Core i7-9700 (8 cores, 65 W) is the highest on Dell's list. Dell lists no K-series, i9 or 10th Gen processors.

Do I need to update the BIOS before upgrading the CPU?

Update it before fitting a 9th Gen processor, especially if your PC came with an 8th Gen one. Dell's documents don't give a minimum BIOS version for each CPU.

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.