Dell Inspiron 15 3520 Upgrade Guide: RAM and SSD Options

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

This guide covers the memory and storage upgrades for the Dell Inspiron 15 3520. The short answer: you get two DDR4 SO-DIMM slots (Dell lists 16 GB as the maximum), one M.2 NVMe SSD slot, and on some units a 2.5-inch SATA bay. Dell doesn't list the processor as an upgradeable part, so this guide doesn't cover CPU upgrades.

At a glance

  • RAM: 2 DDR4 SO-DIMM slots, 16 GB total maximum as listed by Dell
  • RAM speed: 2666 MT/s on non-Type-C units, 3200 MT/s on Type-C units
  • SSD: one M.2 NVMe slot taking 2230 (up to 1 TB) or 2280 (up to 2 TB) drives
  • 2.5-inch SATA HDD bay up to 2 TB, but not on units with a 4-cell battery
  • Dell documents this laptop under regulatory model P112F, so check the label on your unit
SODIMM memory slots2 × DDR4 SO-DIMM · up to 16 GB total · 3200 MT/s
M.2 SSD slot (2230/2280)SSD M.2 2230 / M.2 2280 (NVMe) · up to 2 TB
2.5" SATA HDD bayHDD 2.5" (SATA) · up to 2 TB
2 × SO-DIMM · DDR4up to 16 GB totalM.2 SSD slot (2230/2280)SSD M.2 2230 / M.2 2280 (NVMe) · up to 2 TB2.5" SATA HDD bayHDD 2.5" (SATA) · up to 2 TB
Schematic of the upgradeable slots (not to scale). Check the owner's manual for their exact positions.

Lifecycle and support

No lifecycle information available.

RAM: two DDR4 SO-DIMM slots, 16 GB maximum

The Inspiron 15 3520 has two user-accessible DDR4 SO-DIMM slots, and Dell lists no soldered memory. Each slot takes a 4, 8 or 16 GB module. Dell's supported configurations are 4, 8 or 16 GB as a single module, 12 GB (4 GB + 8 GB), 8 GB (2 x 4 GB) and 16 GB (2 x 8 GB). Dell lists 16 GB as the maximum total.

Whether two 16 GB modules (32 GB) work is not confirmed, so treat that as unverified rather than a safe upgrade. Dell's documents don't state ECC or registered support. It only lists standard DDR4 modules, so assume ordinary non-ECC, unbuffered memory.

Speed depends on your version. Non-Type-C units run memory at 2666 MT/s and Type-C units at 3200 MT/s, so faster modules will be slowed down to whatever your unit supports. Dell notes that 11th-gen Intel Core versions don't offer Type-C. A mixed 4 GB + 8 GB setup is listed as supported, but only matched 2 x 4 GB and 2 x 8 GB pairs are described as dual-channel.

Buying tips

  • For the best performance, buy a matched pair of two 8 GB DDR4 SO-DIMMs rather than mixing sizes.
  • Don't pay extra for 3200 MT/s modules if your unit is non-Type-C, as it runs at 2666 MT/s.
  • Skip 2 x 16 GB kits unless you accept the risk: Dell only lists 16 GB total.
  • Buy standard laptop DDR4 SO-DIMMs, not ECC or registered modules.

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Storage: M.2 NVMe SSD slot and optional 2.5-inch SATA bay

The main storage slot is an M.2 NVMe slot that takes either 2230 or 2280 length drives. Dell's listed options are: 2230 Gen3 x4 up to 1 TB, 2230 Gen4 x4 up to 1 TB, 2280 Gen4 x4 up to 2 TB, and 2280 QLC Gen3 x4 up to 1 TB. Dell lists both Gen3 and Gen4 drives, but a Gen4 drive may run at Gen3 speed on some CPU variants. Check which standoff position your unit uses for 2230 or 2280 before you buy. There is also a separate M.2 2230 slot for Wi-Fi and Bluetooth, which is not for storage, and the SD 3.0 card reader is not a drive upgrade slot.

Some units also have a bay for a 2.5-inch 5400 rpm SATA hard drive, listed up to 2 TB. Units with a 4-cell battery do not support a hard drive at all. A drive caddy and cable may be needed. Dell doesn't document a thickness limit; a standard 7 mm drive is the safest choice, but that isn't confirmed. It's also unclear whether an HDD and an M.2 SSD can be used together, since Dell describes the computer as supporting one of the listed configurations.

Buying tips

  • Choose an NVMe M.2 drive, not a SATA M.2 drive: Dell lists only PCIe NVMe options.
  • A 2280 drive is the only way to reach 2 TB on the M.2 slot; 2230 drives top out at 1 TB.
  • Don't pay a premium for a Gen4 drive, as it may run at Gen3 speed on some units.
  • Check your battery size and whether your unit has a caddy and cable before buying a 2.5-inch drive.
  • If you want a 2.5-inch drive, a 7 mm model is the safest guess, but it is unconfirmed.

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How to upgrade

Before you start

  • Check the label on your unit. Dell documents this laptop as the Inspiron 15 3520 with regulatory model P112F, not P106F.
  • Back up your files, or clone your old drive first if you are replacing the SSD.
  • Find out whether your unit is Type-C or non-Type-C, since this sets the RAM speed.
  • Check your battery size: 4-cell units don't support a 2.5-inch hard drive.
  • Download Dell's owner's and service manuals for exact disassembly steps.
  • Have a small screwdriver ready, and work on a clean, non-carpeted surface.

Steps

  1. Back up your data
    Copy important files to an external drive or cloud storage, or prepare to clone your current drive before swapping it.
  2. Power off and unplug
    Shut the laptop down fully (not sleep), unplug the charger and any other cables or cards. Follow Dell's manual for any battery precautions before touching internal parts.
  3. Ground yourself
    Touch bare metal or use an anti-static strap before handling components, and hold modules and drives by their edges.
  4. Open the case
    Turn the laptop over and follow the removal steps in Dell's service manual for the base cover. Take care with the cover's clips and any screws, and keep screws organised.
  5. Install the RAM or drive
    For memory, follow Dell's memory-module procedure and seat the module fully in its slot. For an M.2 SSD, check whether your unit's standoff position matches a 2230 or 2280 drive, then fit the drive as the manual describes. For a 2.5-inch drive, check whether you need a caddy and cable.
  6. Close the case
    Refit the base cover and screws as per the manual, then reconnect power.
  7. Check that it's recognised
    Start the laptop and open the BIOS setup screen to confirm it shows the new memory size or drive. Then install or restore your operating system if you replaced the drive.

Good to know

  • Dell documents this laptop under regulatory model P112F, not P106F. Check the label on your unit.
  • Dell lists 16 GB as the RAM maximum. Whether 2 x 16 GB works is not confirmed.
  • RAM runs at 2666 MT/s on non-Type-C units, so faster modules will be slowed down.
  • Only matched 2 x 4 GB and 2 x 8 GB pairs are described as dual-channel.
  • It is unclear whether a hard drive and an M.2 SSD can be used together, and 4-cell battery units can't take a hard drive.
  • A Gen4 SSD may run at Gen3 speed on some CPU variants.
  • Dell doesn't document a thickness limit for the 2.5-inch drive.
  • The specs mention a nano-SIM slot, but don't assume your unit has mobile broadband.
  • Dell doesn't list the CPU as upgradeable, so this guide doesn't cover processor upgrades.

Frequently asked questions

How much RAM can the Dell Inspiron 15 3520 take?

Dell lists 16 GB as the maximum total, using two SO-DIMM slots. Whether 2 x 16 GB (32 GB) works is not confirmed.

What type of RAM does the Inspiron 15 3520 use?

It uses DDR4 SO-DIMM laptop memory in modules of 4, 8 or 16 GB. Non-Type-C units run it at 2666 MT/s and Type-C units at 3200 MT/s.

Can I add a bigger SSD to the Inspiron 15 3520?

Yes. The M.2 slot takes a 2230 drive up to 1 TB or a 2280 drive up to 2 TB, both PCIe NVMe. Check which standoff position your unit uses.

Does the Inspiron 15 3520 support PCIe Gen4 SSDs?

Dell lists both Gen3 and Gen4 NVMe drives. However, a Gen4 drive may run at Gen3 speed on some CPU variants.

Can I fit a 2.5-inch hard drive in the Inspiron 15 3520?

Some units can take a 5400 rpm SATA drive up to 2 TB, but units with a 4-cell battery cannot. A caddy and cable may be needed, and the thickness limit is not documented.

Can I upgrade the CPU in the Inspiron 15 3520?

Dell's documents don't list the processor as an upgradeable part, so this guide only covers RAM and storage.

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.