Cheapest server & workstation RAM ranked by price per GB

Server and workstation memory: ECC, RDIMM and LRDIMM explained

The 689 kits on this page are the ones detected as server or workstation memory: ECC, registered, load-reduced, or sold for Xeon, EPYC and Threadripper platforms. They are ranked by price per gigabyte from £1.07/GB, median £10.58/GB. The cheapest module right now is Lafeier 16GB PC3-8500R DDR3 1066Mhz CL7 240Pin ECC REG Memory RAM 1.5V… at £17.11. Compared with consumer kits the per-GB price is higher and the choice is less about speed and more about getting the exact type your board's qualified vendor list (QVL) allows.

• ECC UDIMM (unbuffered ECC): looks like desktop memory with one extra chip for error correction. Used by entry servers, many workstation boards, Ryzen PRO and Xeon E systems. Some consumer AMD boards accept it and run ECC; Intel consumer boards generally will not use the ECC function.
• RDIMM (registered): a buffer chip on the module lets a server run far more memory across more slots. Standard for two-socket Xeon Scalable, EPYC and the 2019 Mac Pro. RDIMMs do not work in desktop boards, and desktop UDIMMs do not work in RDIMM-only servers.
• LRDIMM (load-reduced): for the very largest capacities per socket; only worth it when you are filling every slot with 64GB or 128GB modules.
• DDR5 RDIMM for Xeon Scalable 4th gen onward and EPYC Genoa or Turin: 4800 to 6400MT/s, a different key from DDR4 RDIMMs, and the on-die ECC that every DDR5 stick has is not the same as full ECC; look for "ECC RDIMM" in the title.

Buying used and refurbished server RAM

Server memory is where the second-hand market is deepest. Data centres retire DDR4 RDIMMs in huge volumes, so a 32GB DDR4-2666 RDIMM often costs a fraction of a new one and, because ECC catches faults, a used module that passes a memory test is a low-risk buy. Amazon Warehouse and refurbished listings show up in the table alongside new stock; a kit marked with a price-drop badge is worth a second look, and the product page shows the price history so you can see whether a listing is genuinely cheap or has simply come down from a spike.

For a home server or NAS build, an ECC UDIMM in a Ryzen or Xeon E board is usually the practical choice. For a rack server, match the speed and rank organisation (1Rx4, 2Rx8) in the title to what is already installed. Mixing ranks and vendors within a channel is a common cause of boot failures on Dell and HPE machines; the safe move is a matched set. Ordinary desktop kits and SO-DIMMs are on their own pages; capacity pages such as 64GB and 128GB include the server modules as well.