Cheapest 8GB DDR4 RAM ranked by price per GB

8GB DDR4 RAM: the second stick, the office PC and the mini PC

8GB of DDR4 is rarely the whole memory of a new build in 2026; it is the module you add. The typical buyer has a laptop from 2016 to 2023 with one 8GB stick fitted and a free slot, an office PC that shipped with a single module, a mini PC or thin client with a fixed workload, or a home server that does one job. The 847 8GB DDR4 kits and sticks above are ranked by price per gigabyte, from £3.50/GB to £81.61/GB (median £8.22/GB); the cheapest right now is HYNIX 8GB (1x 8GB) 2RX8 PC4-17000 DDR4-2133MHZ HMA41GU6AFR8N-TF UDIMM … at £27.99.

Adding a second 8GB: getting the match right

Most machines sold with 8GB of DDR4 have it as a single module, which means they run in single channel. Adding a second 8GB stick gives you 16GB and dual channel at the same time, which noticeably helps integrated graphics and anything memory-bound. To get it right:

• Match the form factor. Laptops and mini PCs take the 260-pin SO-DIMM; desktops take the 288-pin DIMM. They are not interchangeable.
• Match the speed if you can. Windows Task Manager shows the fitted module's speed under Performance, then Memory. A faster stick will run at the slower one's speed, which is harmless; a slower stick pulls both down.
• Prefer the same rank and chip width. Most 8GB DDR4 modules are single-rank. Matching that, and the brand where possible, gives the best chance of a stable pair; our compatibility guide walks through the checks.

Speeds and latency

Speeds here run from 2,133 to 3,600MHz. Laptops and prebuilt PCs mostly run at 2666 or 3200MHz at JEDEC timings (CL19 at 2666, CL22 at 3200), and buying an enthusiast kit for them is wasted money because they cannot enable XMP. On a desktop with a gaming board, 3200MHz CL16 is the sweet spot for AM4 and Intel; remember to switch on XMP or DOCP in the BIOS, or the module runs at 2133 or 2400.

When 8GB DDR4 is the wrong buy

For a new gaming PC, 8GB is not enough, and even a 2x4GB kit at this total will feel cramped with a browser open next to a game. The 16GB DDR4 page is the starting point, and the per-GB price of a 2x8GB or 2x16GB kit is usually lower than a single 8GB stick here. If your machine has only one slot and 8GB is fitted, the upgrade is a single 16GB module rather than another 8GB.

Reading the table

The For column marks desktop, laptop and server modules; 8GB DDR4 ECC UDIMMs and RDIMMs from small servers appear too, and will not work in a consumer board. Kingston ValueRAM, Crucial's plain modules and similar JEDEC-speed parts are the reliable no-frills choices, and at this size the brand difference is a few pounds. Our laptop upgrade guide covers opening the case and checking for soldered memory. Older machines belong on the 8GB DDR3 page; see also all 8GB memory and every DDR4 kit.