DDR4 RAM Prices per GB

If your current CPU and motherboard use DDR4, absolutely — DDR4 is the value tier right now. The 2026 DDR5 supply crunch pushed DDR5 $/GB several times higher than DDR4, so topping up or maxing out an existing DDR4 system is dramatically cheaper than a platform upgrade (which also means a new CPU and board). DDR4 is a mature generation with a deep used and decommissioned-server supply, so the $/GB floor on this board stays low. The honest caveat: you cannot put DDR4 in a DDR5 board or vice versa, and if you're building brand new on a current platform you're likely forced onto DDR5. For extending the life of a DDR4 machine, though, it's one of the cheapest performance-per-dollar moves available.

For a homelab or NAS, often yes — it's one of the best value plays in the whole memory market. When datacenters decommission servers, registered ECC RDIMMs (and LRDIMMs) hit the secondary market in huge quantity at a steep discount, so the $/GB can be a fraction of new desktop memory, especially for large 32/64GB modules. The tradeoffs: RDIMM/LRDIMM only works in server and workstation boards that accept registered memory (it will not post in a normal desktop), the modules run a bit slower and sometimes hotter, and you inherit no meaningful warranty. But for a virtualization host, a TrueNAS/ZFS box, or a Proxmox lab where you want maximum ECC-protected RAM per dollar, used server RDIMM is hard to beat. Filter this board to ECC and used/refurbished, sort by $/GB, and check the module type matches your board.

The floor moves, so check the live board above, but DDR4 remains the value tier. Because DDR5 has taken the price-spike hit and DDR4 is a mature, oversupplied generation with a deep used and decommissioned-server market, DDR4 $/GB stays low — often a small fraction of current DDR5. As of this board, the cheapest DDR4 rows floor in the low single digits per GB, and used server RDIMMs can go lower still. Anything near the top of this ranking is a strong buy. The catch is platform: DDR4 only helps you if your CPU and motherboard take DDR4 — you cannot mix generations.

Yes, usually. ECC (error-correcting) memory carries an extra DRAM chip per rank to detect and fix single-bit errors, and registered/buffered ECC RDIMMs/LRDIMMs add a register that eases the load on the memory controller for high-capacity server configs. That extra silicon and the server-grade positioning mean ECC modules often list at a different $/GB than plain desktop UDIMMs — sometimes higher new, but frequently LOWER on the used/recertified server market because decommissioned server RDIMMs flood in cheap. ECC only works if your CPU and board support it (most consumer platforms don't; server, workstation, and some AMD boards do). If you're building a NAS, a homelab, or a workstation that supports it, ECC is worth it for data integrity — and the used-server $/GB can be a bargain. Use the ECC filter above to compare.