Server memory

Server memory in this category covers DDR3, DDR4 and DDR5 DIMMs for rack, tower and workstation systems, from small business file servers to virtualisation hosts. Our range has over 400 modules from brands including Dell, Samsung, HP Enterprise, Kingston and Micron. Many are registered modules, and unbuffered options are available too.

How to choose server memory

Memory generation. DDR3, DDR4 and DDR5 are not interchangeable, so check which generation your server's motherboard supports before anything else. DDR4 is the largest group in our range, DDR5 covers newer platforms, and a smaller number of DDR3 modules suit older machines. DDR4 and DDR5 use 288-pin DIMMs, while DDR3 uses 240-pin.

Registered or unbuffered. Registered (buffered) modules contain a register chip that lets a server carry more memory per channel, and most dual-socket and larger servers expect them. Unbuffered modules suit entry-level servers and workstations built for them, and load-reduced modules exist for very high capacities. The two main types cannot be mixed in one system, and the server manual states which one it takes.

Capacity and module layout. Modules in our range run from 4 GB to 128 GB, and 16 GB, 32 GB and 64 GB are the sizes listed most often. Fewer, larger modules leave free slots for later upgrades, while filling every memory channel evenly gives better bandwidth. Most listings are single modules, though some are kits such as 8 x 8 GB.

Speed and voltage. Speeds in our range include 2133, 2666, 2933 and 3200 MHz for DDR4 and 5600 MHz for DDR5. When modules of different speeds share a server, they generally run at the slowest speed or at the limit of the processor, so buying faster modules than the platform supports gains nothing. Voltage follows the generation: 1.2 V is typical for DDR4, 1.1 V for DDR5 and 1.35 V for low-voltage DDR3L.

Server memory brands we carry

• Dell, HP Enterprise, Lenovo, Fujitsu and Cisco: these are server makers, and their branded modules are matched to their own systems, which makes them easy to specify by part number.
• Samsung: one of the largest DRAM chip manufacturers in the world, producing the memory chips used in many server modules.
• SK hynix: a South Korean DRAM maker whose chips are widely used in server memory from both its own and other brands.
• Micron: a major DRAM manufacturer that makes server modules from its own chips.
• Kingston: known for its Server Premier range, which is tested against specific server platforms.

Also in our range: GoodRAM and unbranded modules.

Server memory FAQ

Can I use desktop RAM in a server?

Usually not. Many servers require registered modules, and desktop RAM is unbuffered and often lacks error correction. Some entry-level servers and workstations accept unbuffered ECC modules, so check the specification of your exact model first.

What is the difference between registered and unbuffered server memory?

Registered memory has a register chip between the memory controller and the DRAM chips, which reduces the electrical load and allows more modules per channel. Unbuffered memory connects directly to the controller, so it supports fewer modules but is simpler. A server is built for one type and will not work with the other.

Can I mix different sizes or speeds of server memory?

Often yes, but it is not recommended. Mixed modules usually force everything to run at the slowest speed, and uneven sizes can unbalance the memory channels and reduce bandwidth. The vendor's population guide shows which combinations are supported.

How do I find out which memory my server needs?

Look up the server model in the manufacturer's documentation for the memory generation, buffering type, maximum speed and slot population rules. You can also read the part number on a module already installed. Modules sold under Dell, HP Enterprise or Lenovo names are normally listed against specific server models.