How much RAM does a dedicated server need?

RAM is the cheapest way to make a server faster, and the most common thing people buy too little of. Running out does not crash a server straight away. It just makes everything slow, as the system starts using the disk as overflow memory.

A rough guide by workload

• A personal site, a VPN or a DNS server: 8 GB is plenty.
• A WordPress or WooCommerce site with steady traffic: 16 GB.
• Agency hosting with a dozen or more client sites: 32 GB.
• A busy database, or several game servers: 64 GB.
• Virtualization with Proxmox, or large in-memory caches: 128 GB and up.

These are starting points. Your own numbers matter more.

Measure what you use now

If you are moving from a VPS or another server, check how much memory is actually in use at your busiest time of day. On Linux, free -h shows it. Ignore the "buff/cache" figure, since Linux fills spare RAM with disk cache and hands it back when needed. Look at "used" and at swap. If swap is being used, you are already short.

Take your peak use and double it. That covers growth and gives the operating system room to cache files, which itself makes the server faster.

Databases love memory

MySQL, MariaDB and PostgreSQL all keep the most-used parts of the database in memory. When the whole working set fits, queries barely touch the disk. When it does not, every miss is a disk read. A database server with too little RAM can feel slow even on NVMe.

A good rule is enough RAM to hold your whole database plus a few gigabytes for everything else. If your database is 20 GB, a 32 GB server is the minimum and 64 GB is comfortable.

Why older servers are such good deals here

Big-memory machines from a CPU generation or two back are often marked down hard. A dual-Xeon server with 128 GB of RAM can cost less than a new machine with 32 GB. If your workload needs memory more than raw CPU speed, those deals are some of the best value you will find.

ECC memory

Server-class Xeon and EPYC machines use ECC RAM, which catches and corrects small memory errors before they corrupt data. For a database or a file server, that is worth having, and on a dedicated server it comes standard.