DDR4 and DDR5 memory: how many GB, dual channel, XMP and EXPO, laptop memory

How much memory you need

Memory (RAM) holds what the computer is working on right now. With too little, the system swaps data to the drive and everything slows down; with a lot, nothing gets faster. The right capacity therefore follows the use:

• 8 GB – too little today even for a browser with many tabs; it only makes sense in the cheapest office machines.
• 16 GB – the sensible base for office, study, home and Full HD gaming.
• 32 GB – 1440p gaming, streaming, photo editing, programming, many programs open at once.
• 64 GB and more – 4K video editing, 3D, virtualisation, large data sets and AI models.

Dual channel: always in pairs

The motherboard reads from two modules at once when they sit in the right slots. Two 8 GB modules are therefore faster than one 16 GB module – with processors that have integrated graphics the difference is marked, because the graphics use system memory as their own. Buy memory as a kit of two (or four) identical modules from one maker; a kit is tested together and guarantees the modules run at the same settings. In our builds from the configurator memory is always paired.

DDR4 or DDR5

The memory type is decided by the motherboard and cannot be swapped – the modules have a different notch and do not fit the wrong slot.

• DDR4 – cheaper, fast enough for office work and gaming; common speeds 3,200 to 3,600 MT/s. Used by AM4 boards and some LGA1700 boards.
• DDR5 – higher bandwidth (from 4,800 MT/s, commonly 5,600–6,400), better headroom for future processors, on-module error checking. The only choice for AM5 and LGA1851 boards.

For a new build DDR5 makes sense today; when extending an existing computer stay with the type the board has. We list the type and the maximum supported frequency in the specifications of both board and module.

Frequency, latency and XMP / EXPO profiles

Memory speed is set by two numbers: frequency (MT/s) and CL latency. Higher frequency and lower CL is better; in practice the difference between 5,600 and 6,400 MT/s in games is a few percent. Memory out of the box runs at its base frequency (DDR4 2,133, DDR5 4,800 MT/s); the XMP profile (Intel boards) or EXPO (AMD boards), enabled with one BIOS setting, brings it to its rated speed. This is not overclocking beyond specification – the profile is tested by the memory maker. On builds from our Písek workshop we enable the profile during testing.

Laptop memory: SO-DIMM

Laptops use the shorter SO-DIMM modules; the type (DDR4 or DDR5) and the maximum capacity are set by the laptop. Check three things before buying:

1. Is the memory replaceable at all? Many thin laptops have soldered memory (often labelled LPDDR); that cannot be extended.
2. How many slots – one or two. With one slot you replace the module, with two you add one.
3. Which type and frequency the laptop supports; a faster module does no harm, it runs at the laptop's frequency.

Upgrading from 8 to 16 GB is the cheapest speed-up for an older laptop. We fit the memory for you at pickup in Písek.

When to mix memory and when not to

An old and a new module work together technically if they are the same type, but the board runs them at the slower one's settings and sensitive boards produce errors. Replacing both with a kit is more reliable. Memory errors show as random crashes and blue screens – a memory test (e.g. MemTest86) is the first diagnosis.

Buying from us

Desktop modules are in the Desktop memory category, SO-DIMM modules in Laptop memory; you filter by type, kit capacity and frequency. Memory in stock ships within 1–2 working days, delivery is free from CZK 6,000 and a 24-month warranty applies. The configurator offers only memory of the right type for the chosen board.