Memory is one of the few PC parts where the wrong purchase does not merely underperform — it does not fit at all. This page covers the four decisions in order: generation, capacity, kit configuration, and speed. None of it requires you to be a specialist.
Your motherboard is built for exactly one memory generation. DDR4 and DDR5 modules both have 288 pins on desktop, but the key notch sits in a different position and the electrical design is different — the wrong generation physically will not go into the slot.
The platform usually decides it:
Rather not look it up by hand? Use our compatibility checker — it covers these platforms and refuses to guess on the ambiguous one.
One thing DDR5 is not: automatically faster in daily use. It has higher bandwidth and starts at higher clocks, and on new platforms it is the only option. But a well-configured DDR4 machine remains entirely capable — there is no reason to replace a platform just to change memory generation. Buy the generation your board takes.
Capacity is the spec you feel every day. Too little produces stutter, tab reloads and swapping to disk; beyond "enough", extra gigabytes mostly sit idle. Honest guidance by workload:
| Browsing, office, study | 16 GB is comfortable. 32 GB removes the question for years. |
|---|---|
| Gaming | 16 GB is the working minimum in current titles; 32 GB is the comfortable standard, and the streaming-plus-Discord-plus-browser reality of actual gaming sessions is exactly what the second 16 GB is for. |
| Photo and video editing | 32 GB as a base; 64 GB pays for itself on 4K timelines, large RAW libraries and heavy multitasking between editor, browser and export. |
| Virtual machines | Each VM takes its slice of physical RAM. 32 GB runs a couple of serious VMs beside the host; 64 GB is the relaxed choice for a home lab. |
| Local AI models | The current genuinely memory-hungry home workload. Small quantised models (7–8B) run in modest RAM, but 13B-class models, long contexts and anything that spills out of GPU VRAM eat system memory fast. 32 GB is the sensible entry, 64 GB the comfortable one if local models are a real part of your work. |
A practical rule: buy for what you will do in the next three years, not for this month. Memory is fitted in minutes but bought most cheaply once.
Desktop platforms read memory over two independent 64-bit channels. Fit two modules in the right slots and the memory controller uses both at once — dual channel — which doubles the available memory bandwidth compared to one module of the same total size. With integrated graphics the difference is dramatic; with everything else it is consistently measurable.
That is why our DDR4 kits are sold as two matched 16 GB modules rather than one 32 GB module: two modules from the same production run, with the same chips and the same timing behaviour, running side by side. Mixing modules of different origin often works, but it is never guaranteed — the platform drops to the settings of the weakest module, or refuses to run stably at all. A matched kit removes that variable.
Speed (e.g. DDR4-3200, i.e. 3200 MT/s — million transfers per second) is how much data the module can move per unit of time. Latency (the CL figure, e.g. CL16) is how many clock cycles the module waits before answering a request. Bandwidth is the width of the pipe; latency is how quickly the tap opens.
In practice, for an intelligent buyer who is not benchmarking for sport:
Out of the box, a motherboard runs memory at a conservative default from the JEDEC standard — that is why a "3200" kit sometimes shows 2133 or 2400 MT/s on first boot. Nothing is broken; the board simply has not been told to use the faster settings yet.
XMP (Intel's name) and EXPO (AMD's name) are pre-tested speed-and-timing profiles stored on the module itself. In the BIOS/UEFI there is a single setting — usually on the first screen — that reads the profile and applies it. Enable it, save, reboot, and the kit runs at its rated speed. Many AMD boards also read XMP profiles (board makers label this DOCP or EXPO compatibility). The installation guide walks through it.
Whether a given kit carries a profile, and at what settings, is part of its spec sheet. On our product pages, anything of that kind we have not yet verified against the current batch is marked [TO CONFIRM] rather than asserted — if it matters to your purchase, ask us first and we check the exact kit that would ship.
Or put them side by side first.