DDR4 vs DDR5 motherboards

A motherboard is built for one memory type. DDR4 and DDR5 modules are keyed differently and will not fit each other's slots, so the choice is made when you buy the board, not when you buy the memory. The short answer: for a new build, buy a DDR5 board, because every current platform requires it. A DDR4 board makes sense in two cases only: you already own good DDR4 and want to reuse it, or you are building as cheaply as possible on AM4 or LGA1700.

Which platforms take which memory

On most sockets there is no decision to make, because the processor's memory controller supports one type only.

So the real DDR4-or-DDR5 question only comes up on LGA1700, plus the wider question of whether to build on an older DDR4 platform at all. For that, see AM5 vs AM4 and LGA1851 vs LGA1700.

LGA1700: the same chipset in two versions

Intel's 12th, 13th and 14th generation processors can drive either memory type, so board makers sold many 600- and 700-series models twice: once with DDR4 slots and once with DDR5 slots. A B760 or Z790 board is one or the other, never both, and the two versions are otherwise close to identical.

The DDR4 version usually carries DDR4 or D4 in its model name, and some makers mark the DDR5 version with D5, but naming is not consistent enough to rely on. Read the memory line in the specification before ordering, and read it twice on an open-box listing, where the title may have been shortened. Fitting the wrong module is not possible without force: the notch is in a different place.

What DDR5 actually changes

• Bandwidth. Standard DDR4 tops out at 3200 MT/s, with enthusiast kits commonly sold at 3600. Standard DDR5 starts at 4800 MT/s, and mainstream kits run at 5600 to 6400, with faster ones available.
• Timings look worse but are not. A DDR5 kit may be rated CL30 or CL36 where a DDR4 kit is CL16. Because each DDR5 cycle is shorter, the real latency in nanoseconds is broadly similar. The gain is in bandwidth, not latency.
• Power regulation moves onto the module. DDR5 runs at a lower voltage than DDR4 and each module carries its own power-management chip, which is one reason DDR5 modules cost more to make.
• Capacity. DDR5 allows larger modules, including the 24 GB and 48 GB sizes that do not exist in DDR4. An older DDR5 board may need a BIOS update before it recognises these.

How much faster it is in practice

Less than the numbers suggest. LGA1700 is the one platform where the same processor can be tested with both memory types, and the pattern there is consistent: when the graphics card is the limit, which is most gaming at high resolution, the difference is close to nothing. When the processor is the limit, fast DDR5 gives a modest lead that varies a good deal from game to game. Work that moves a lot of data through memory, such as file compression, code compilation and some rendering and scientific tasks, benefits more.

Nobody should replace a working DDR4 system for the memory alone. The argument for DDR5 is mostly about the platform that comes with it, not the modules.

XMP and EXPO: rated speed is not automatic

Whichever type you buy, the memory starts at a conservative default speed. The speed printed on the box is an overclocking profile that you switch on in the BIOS: XMP is Intel's name for it and EXPO is AMD's. Many DDR5 kits carry both profiles. Most AM5 boards will also read an XMP profile, but that is a board feature, so check the memory support list for the board you are buying.

Chipset matters here. On Intel, Z-series boards and B- and H-series boards from B560 onwards allow memory profiles, but the entry-level H610 and H810 do not, so fast memory is wasted on them. On AMD, every AM5 chipset, including A620 and B840, supports EXPO.

Two modules or four

Running four DDR5 modules at a high-speed profile is much harder for the memory controller than running two. Board specifications show this openly: the highest supported speeds are quoted for two modules, and the figures for four are lower. Buy the capacity you need as a pair, and treat the second pair of slots as a fallback rather than a plan. Mini-ITX boards, with only two slots, lose nothing here.

One DDR5 habit worth knowing before an open-box board arrives: the first start, and any start after the BIOS settings are cleared, includes memory training. The screen can stay black for a minute or more, longer with large kits, while the fans spin. That is normal and not a sign of a dead board. Our day-one checklist covers what to look for if it goes on much longer.

When a DDR4 board is still the right buy

• You already own 16 GB or 32 GB of decent DDR4 and are moving to a 12th to 14th gen Core processor. A DDR4 version of a B760 or Z790 board lets you carry it over and spend the difference on the CPU or graphics card.
• You are upgrading an AM4 system in place. A Ryzen 5000 processor in a B550 board with the memory you have is still one of the cheapest worthwhile upgrades in PC building.
• The budget is tight and every pound counts. Older DDR4 boards turn up regularly among Amazon Warehouse offers, and used DDR4 is easy to find.

The cost of going this way is that it is a dead end. DDR4 will not move with you to AM5, LGA1851 or anything later, so the memory and the board will both be replaced at the next upgrade.

When to buy DDR5

For any new AM5 or LGA1851 build the question does not arise. On LGA1700, choose the DDR5 version if you are buying memory anyway: the kit will carry forward to your next platform, and the DDR5 board is usually the easier one to resell. Compare the price of the two board versions and of the memory on the day you buy rather than assuming one is cheaper, because memory prices move a lot from year to year.

Before you order

• Confirm the memory type in the board's specification, not just its name.
• Check the chipset allows memory profiles if you are paying for fast memory.
• Buy two modules, not four, unless you need the capacity.
• Look at the board's memory support list if you are buying a very fast or very large kit.
• Laptop (SO-DIMM) and server (registered) modules do not work in ordinary desktop boards.

For everything else that goes into the decision, start with how to choose a motherboard.