DDR5 vs DDR4 RAM: Which Should You Buy?

The short answer

Buy whatever your motherboard takes. DDR5 and DDR4 are not interchangeable: the notch sits in a different place, so a DDR5 stick will not go into a DDR4 slot or the other way round. For a new PC on AMD AM5 or Intel Core Ultra 200S that means DDR5, because those platforms take nothing else. For a PC that already runs DDR4, the sensible upgrade is more DDR4.

If you want the basics of what RAM does first, start with our guide to what RAM is. The table below sets the two generations side by side, with the specs from Kingston and the lowest UK prices we found this week.

Prices are including VAT and were checked on 2 November 2026.

Speed and latency: DDR4-3600 vs DDR5-6000

DDR5 wins on bandwidth, not on raw response time. JEDEC speeds for DDR5 begin at 4800 MT/s, where DDR4 stops at 3200 MT/s. Kingston adds that DDR5 doubles the banks and the burst length and splits each module into two independent 32-bit subchannels, which helps it move data more efficiently in games and heavy applications.

Latency is where the gap closes. Kits list a CL number, which counts clock cycles, so a bigger CL on a faster kit is not automatically slower. To compare, convert to nanoseconds: CL x 2000 divided by the speed in MT/s. Crucial notes that CL numbers climbed along with speeds, which kept true latency roughly level across generations.

The matchup people search for most is DDR4 3600MHz against DDR5 6000MHz. Strictly, both figures are MT/s, not MHz. Worked through the formula, a DDR4-3600 CL16 kit lands at about 8.9 ns and a DDR5-6000 CL30 kit at 10 ns. So the DDR4 kit answers a touch sooner, while the DDR5 kit moves far more data per second. Engadget puts a slow DDR5-4800 CL40 kit at nearly 17 ns, which shows how much the choice within DDR5 matters too.

For games, the difference is smaller than the spec sheets suggest. Engadget reports that no game needs a particular DDR5 speed and that very fast DDR5-7200 and DDR5-8400 kits only marginally raise frame rates when the CPU is the limit. Our guide to RAM speed and latency goes through the maths in more detail.

Which one fits your PC?

Check the motherboard, not just the processor. AMD AM5 boards for Ryzen 7000 and 9000 and Intel boards for Core Ultra 200S (LGA 1851) take DDR5 only. Intel 12th to 14th gen Core chips sit in the middle: Intel lists the Core i5-14600K for both DDR5 5600 and DDR4 3200, so those builds came with either a DDR4 or a DDR5 board. The board manual or the slots themselves settle it.

On a DDR5 platform, AMD builds usually aim for DDR5-6000 CL30. Buying guides call it the sweet spot because it lines up with the memory controller clock on Ryzen 7000 and 9000, even though AMD only guarantees DDR5-5600 on Ryzen 9000 and DDR5-5200 on Ryzen 7000. Intel officially supports DDR5 up to 6400 MT/s on Core Ultra 200S, and Newegg recommends DDR5-6000 to 6400 there. Every kit at the AMD sweet spot is on our DDR5-6000 CL30 page.

Laptops follow the same rule with smaller sticks. Laptop memory is SO-DIMM, which does not fit a desktop slot, and DDR5 SO-DIMM does not fit a DDR4 laptop either. Kingston's FURY Impact range shows the split: its DDR4 SO-DIMMs run at 3200 MT/s, its DDR5 SO-DIMMs go up to 6400 MT/s. Corsair notes that some laptops have memory soldered to the board that cannot be upgraded, so check the spec sheet first. Our DDR5 laptop RAM and DDR4 laptop RAM pages list the kits we track.

Price per GB in the UK: is DDR4 still cheaper?

Compare price per GB, not the price of a single kit. This week the median DDR4 desktop kit costs £9.06 per GB and the median DDR5 desktop kit £16.75 per GB. We track 189 DDR4 and 321 DDR5 desktop kits across Amazon.co.uk, AWD-IT, Box, CCL, Laptops Direct, Overclockers UK and Scan.

DDR4 is no longer the automatic budget pick it once was. Samsung, SK hynix and Micron all announced DDR4 end of life in 2025 to shift capacity to DDR5, LPDDR5 and HBM. TrendForce reported that in July 2025, 8GB PC DDR4 modules became more expensive than 8GB DDR5 modules, a rare price inversion. In June 2026 it added that some device makers were moving designs from DDR4 back to DDR3 because of the shortage.

DDR5 has been through its own surge. Overclock3D followed one Crucial Pro DDR5-6000 CL36 32GB kit on Amazon UK: £79 on 18 September 2025 and £422 on 14 October 2026, about 5.3 times as much. That is one kit at one shop, not a UK average, but it shows why the comparison changes from month to month.

Every kit, with the shops side by side, is on our DDR5 RAM prices and DDR4 RAM prices pages.

When is switching to DDR5 worth it?

When you are buying a new platform anyway. Moving from DDR4 to DDR5 means a new motherboard and often a new CPU, so the memory is only part of the bill. If your current PC runs well and simply runs out of memory, a bigger DDR4 kit fixes that and nothing else needs to change.

For a fresh build, DDR5 is the only choice on current AMD and Intel platforms. Buy a matched kit of two sticks rather than two separate sticks: mainstream desktops are dual channel, and Newegg notes that filling four slots makes high speeds harder to hold. For gaming with a browser and chat open, Newegg points to 32GB, which means a 2 x 16GB kit. Our guide on how much RAM you need covers the other sizes.

What we do not know yet

We compare prices and specifications; we do not benchmark RAM. Our data cannot say how large the gap between DDR4 and DDR5 is in a given game or program. That depends on the CPU, the graphics card and the workload, so we point to the sources above.

We also do not know where the gap in price per GB goes next. Our UK price series is still young. Change in the median price per GB over 4 weeks: not measured yet. Change since 13 October 2026: not measured yet. Once enough weeks are in, these lines will show firm figures.

Common mistakes

• Buying DDR5 for a DDR4 board. The sticks will not physically fit. Check the board manual before you compare prices.
• Judging latency by the CL number alone. DDR5-6000 CL30 and DDR4-3200 CL16 both work out to 10 ns. Convert to nanoseconds before you decide one kit is slower.
• Leaving the profile switched off. Without XMP or EXPO, a DDR4-3600 or DDR5-6000 kit runs at its default speed, so you pay for speed you do not use.
• Mixing old and new sticks. Adding a second kit later to reach four sticks can pull the speed down. A matched two stick kit is the safer buy.
• Switching platforms for the memory alone. If more capacity is all you need, more DDR4 costs far less than a new board, CPU and DDR5 kit.