The most common RAM-buying mistake is ordering memory that physically will not fit. DDR4 and DDR5 look similar, but they are not interchangeable. This guide shows you how to find out which type your computer uses and what else to check before you buy.

Quick answer

• Your computer supports either DDR4 or DDR5 — the motherboard decides, not the processor alone.
• DDR4 modules will not fit a DDR5 slot, and DDR5 will not fit a DDR4 slot. The notch in the connector is in a different place.
• Desktops use full-length DIMM modules; laptops and mini PCs use shorter SODIMM modules.
• The easiest way to be sure is our Memory Configurator: choose your make and model and we show compatible memory.

DDR4 vs DDR5 at a glance

How to check which RAM your computer uses

1. Use the Memory Configurator. Select your computer's manufacturer and model on our Memory Configurator.
2. On Windows: open Task Manager ? Performance ? Memory. The top-right corner shows the memory type and speed, and "Slots used" shows how many slots are free.
3. On a desktop: look up your motherboard model (it is printed on the board, or shown in System Information) and check the manufacturer's specification page.

Other things to check before you buy

Is the laptop memory soldered?

Many thin laptops have memory soldered to the motherboard, which cannot be upgraded. Check the manufacturer's specifications or our configurator before ordering.

Speed

Faster memory is backwards compatible: if you install a 5600MT/s DDR5 module in a system that supports 4800MT/s, it will run at 4800MT/s. You will not damage anything — you simply will not gain the extra speed.

XMP and EXPO profiles

Gaming memory such as Kingston FURY often includes overclocking profiles: Intel XMP or AMD EXPO. These let a compatible motherboard run the memory at its rated speed with one setting in the BIOS. Without the profile enabled, the memory runs at standard speed.

ECC and registered memory

Servers and workstations often need ECC (error-correcting) memory, sometimes registered (RDIMM). These are not interchangeable with standard desktop memory. See our Server Premier range.

Matching kits

For best stability, install memory as a matched kit (for example 2 × 16GB) rather than mixing different modules.

How much RAM do I need?

• 8GB: basic web browsing and office work
• 16GB: the sweet spot for most home, office and gaming PCs
• 32GB: serious gaming, streaming, photo and video editing
• 64GB and above: professional video, 3D work, virtual machines

Shop memory

• DDR5 memory
• DDR4 memory
• Find memory for your device

Still unsure? Call us on 01422 363983 (Mon–Fri, 9am–5pm) with your computer model and we will check compatibility for you.