Cheapest 8GB desktop RAM ranked by price per GB

8GB desktop RAM: office PCs, older towers and the cheapest top-up

8GB is no longer enough for a new desktop build, but it is still the most useful module size for keeping existing PCs working: office machines, family computers and older towers that shipped with 4GB or a single 8GB stick. The 356 8GB desktop kits and modules above are ranked by price per gigabyte, from £2.25/GB to £147.69/GB with a median of £8.21/GB; the cheapest right now is Timetec 8GB DDR3L / DDR3 1600MHz (DDR3L-1600) PC3L-12800 / PC3-12800 (… at £17.99.

A single 8GB stick or 2x4GB?

Most listings here are single 8GB DIMMs, with a smaller number of 2x4GB kits. A 2x4GB kit runs in dual channel, but it fills two slots with a size most people will outgrow. In a two-slot PC, a single 8GB stick now and a matching second one later is the more flexible route, and in a PC that already has one 8GB stick fitted, adding a second gives 16GB in dual channel for the price of one module.

Where 8GB desktop modules go

• Small-form-factor office PCs such as the Dell OptiPlex, HP ProDesk and EliteDesk and Lenovo ThinkCentre ranges, which very often shipped with one 8GB stick and one or three free slots. A second matching 8GB is the single best upgrade for a refurbished business PC.
• DDR3 towers from about 2011 to 2015, Intel 2nd to 4th generation and AMD FX. An 8GB DDR3 DIMM at 1600MHz is the standard part (see DDR3-1600), and most four-slot boards of that era take up to 32GB.
• DDR4 desktops from 2015 on, where an 8GB DDR4 module at 2400, 2666 or 3200MHz is the most common stick in prebuilt PCs.

8GB DDR5 desktop modules exist but are uncommon and usually poorer value per GB than 16GB ones; a DDR5 machine is better served by the 16GB desktop page.

Gotchas

Desktop DIMMs have 288 pins for DDR4 and DDR5 and 240 for DDR3, and each generation is keyed differently. Laptop SO-DIMMs are shorter and will not fit a desktop slot, and server RDIMMs, which are the same length, need a board that supports registered memory. When adding to an existing stick, match the generation and speed; prebuilt PCs are usually happy with a different brand at the same specification, but an identical module is the safest choice. On a four-slot board, fit a pair in the slots the manual marks for dual channel, usually the second and fourth from the CPU. One more trap on old machines: 32-bit Windows cannot use more than about 3.5GB, so an older install may need moving to 64-bit before an upgrade to 8GB or more makes any difference.

Reading the table

The For column should say Desktop. If the ECC or Buffered column is ticked, or the title contains a code like PC3-12800R or PC4-2400T-R, the module is a server part and belongs on the 8GB server page; it will not boot in a consumer board. Price differences at 8GB are small in pounds, so the £/GB ranking plus the rating count is the whole decision, and Amazon Warehouse returns are often the cheapest per gigabyte. For more context see all desktop RAM, every 8GB module, the 8GB laptop page, and the guide to how much RAM you need.