COMPUTER MEMORY BY SPECIFICATION
NEMIX RAM
Computer Memory by Specification
Six form factors, 4,300+ modules, DDR2 through DDR5. If you already know what your board takes, pick it below. If you don't, this is the short version — and it's the question we're asked most.
Start here: does your machine need ECC?
ECC memory detects and corrects single-bit errors before they corrupt data. Servers, workstations and NAS units generally require it — many won't boot without it. Desktops and laptops generally can't use it. This is not a preference. Your board decides, and the wrong choice usually means the machine won't post.
The Six Computer Memory Form Factors, in plain English
RDIMM — ECC Registered DIMM
The workhorse of server memory. A register buffers the address and command lines, so the board can drive far more modules than it otherwise could. What most Xeon and EPYC servers take. If you have a rack server, this is almost certainly your answer.
LRDIMM — ECC Load-Reduced DIMM
Buffers the data lines as well as the address lines, which cuts electrical load further and lets you reach the highest total capacities a platform supports. Where you go when RDIMM can't get you enough memory — the largest kits here run to 1.5TB. Costs more per GB; only use it if your board and your capacity target call for it.
ECC UDIMM — Unbuffered ECC UDIMM
Error correction without the register. Entry-level servers, workstation boards, and most NAS units. Common on Supermicro, ASRock, ASRock Rack, MSI, GIGABYTE, ASUS, Gaming/AI Motherboards and similar single-socket boards.
ECC SODIMM — Unbuffered ECC SODIMM
The laptop-sized module in an ECC version. Mobile workstations, compact NAS units, edge and embedded systems.
UDIMM — Unbuffered, NON-ECC UDIMM
Standard Desktop Memory. No register, no error correction.
SODIMM — Unbuffered, NON-ECC SODIMM
Standard Laptop Memory. mini-PC and all-in-one, Small form factor SFF
Some of the Rules to know about when Selecting Memory for your System
You cannot mix registered and unbuffered memory in the same system — not in different channels, not in different slots.
- Rank matters. A board that takes 2Rx4 may not run 4Rx4 at all, or may run it at a lower speed. Every module here lists its rank.
- Faster memory is not always better. Populate more slots and many platforms automatically drop the speed. The stated rating is a maximum, not a guarantee.
- Physical fit is not compatibility. DDR4 and DDR5 modules are keyed differently and won't cross-fit, but two DDR4 modules that both fit the slot can still be wrong for your board.
Not sure which you need? Search your machine or its part number directly — PowerEdge R750, MBD-X13SRN-H, DS923+ — and we'll show only what fits it. Or contact our team; we've been matching memory to machines since 1993.
NEMIX RAM can deliver any Configuration your Fleet Requires
Lifetime Replacement Warranty on every Module.
Purchase orders, net terms and volume pricing for business, government and education buyers.
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