Cheapest 8GB server RAM ranked by price per GB

8GB server RAM: DDR3 and early DDR4 modules for older servers

8GB is a small module by server standards, and nearly everything at this size is for older hardware: DDR3 registered DIMMs for retired Xeon machines, plus early DDR4 RDIMMs and ECC UDIMMs. The 258 8GB server and workstation modules above are ranked by price per gigabyte, from £1.78/GB with a median of £10.58/GB; the cheapest right now is Josenidny 8GB Memory RAM 2RX8 1.35V DDR3 PC3L-12800E 1600MHz 240 Pin E… at £14.21. Most are used or refurbished, pulled from data centres in large numbers, which is why the prices per stick are so low.

Which machines take 8GB server modules

• DDR3 RDIMM (titles such as PC3-10600R, PC3L-10600R or PC3-12800R): Xeon 5500 and 5600 servers like the Dell PowerEdge R610 and R710 and HP ProLiant G6 and G7, and Xeon E5 v1 and v2 machines like the PowerEdge R620 and R720 and ProLiant Gen8. Many of these now live on as home-lab and NAS boxes.
• DDR3 ECC UDIMM (PC3-12800E and similar): entry servers and small towers that do not take registered memory, such as the HP ProLiant MicroServer Gen8 and Xeon E3 v1 to v3 systems.
• DDR4 RDIMM (PC4-2133P, PC4-2400T or PC4-2666V, with an R in the suffix): Xeon E5 v3 and v4 servers such as the PowerEdge R630 and R730 and ProLiant Gen9, where 8GB was the entry module size.
• DDR4 ECC UDIMM: Xeon E3 v5 and v6 and Xeon E-2100 and E-2200 machines, and Ryzen systems on boards that support ECC.

DDR5 server modules start at 16GB, so this page is almost entirely DDR3 and DDR4; current servers belong on the 16GB and 32GB server pages.

Gotchas: registered, unbuffered, voltage and ranks

The letter after the speed code tells you the type: R is registered, E is ECC unbuffered, L is load-reduced and U is ordinary unbuffered. They do not mix. An RDIMM-only server will not boot with UDIMMs, a UDIMM board will not take RDIMMs, and LRDIMMs cannot share a server with RDIMMs. None of them work in a desktop PC except ECC UDIMMs on boards that support them; see the ECC RAM page for that case.

On DDR3, PC3L modules are the 1.35V low-voltage version and PC3 the 1.5V one; servers run either, but a mixed set runs at 1.5V. The rank code (1Rx4, 2Rx4, 2Rx8) matters too: matching the rank and speed of the modules already fitted avoids the boot errors Dell and HPE machines are known for, and the whole bank runs at the speed of the slowest module. Filling three DIMMs per channel on these older Xeons lowers the memory speed further.

Is 8GB the right module size?

Only when the server has plenty of slots and the aim is a modest total, or you are matching modules already installed. For a two-socket R720 with 24 slots, sixteen 8GB sticks reach 128GB cheaply, but 16GB modules reach the same total in half the slots and leave room to grow. For a DDR3 box, check the price per GB of both sizes before deciding.

Reading the table

The ECC and Buffered columns show the module type, and the title usually carries the full PC3 or PC4 code. If you need an ordinary 8GB desktop stick, use the 8GB desktop page instead. The Warehouse RAM guide covers buying used memory safely, and the server and 8GB hubs show every related module.