How Much RAM Does a Modded Minecraft Server Need?

Short answer: a small modpack with under 50 mods usually runs on 4–6 GB of RAM. A medium pack of 100–200 mods needs 6–10 GB, and large "kitchen sink" packs with 300 or more mods need 10–16 GB. Start from the server RAM the modpack's author recommends, then add about 1 GB for every 5 players beyond the first few.

RAM by modpack size

The pack's own page on CurseForge or Modrinth often lists a recommended server RAM. Use that as the minimum: pack authors test with their own mod list.

Why modded servers need so much more RAM

• Every mod adds content that must stay loaded. New blocks, items, recipes and entities all live in memory from the moment the server starts. A large pack can use several gigabytes before anyone joins.
• Modded world generation is heavier. Packs that add biomes, structures and dimensions make every new chunk more expensive to generate and store.
• Automation runs all the time. Machines, pipes and farms in tech mods keep working in loaded chunks, and chunk loaders keep those areas loaded even when no one is nearby.
• Mod loaders have their own overhead. Forge and NeoForge use more memory than Fabric for a similar mod list.

RAM isn't the only bottleneck

Modded servers are often limited by the CPU before they run out of memory. Minecraft runs most of its game logic on a single thread, and large tech bases add a lot of work to every tick. If the server lags while memory still has room to spare, a faster CPU will help far more than extra RAM. See Minecraft Server CPU: What Actually Matters.

Storage speed matters too. Large modded worlds read and write a lot of chunk data, so NVMe storage makes a visible difference to chunk loading.

Signs a modded server needs more RAM

• The server crashes during start-up while loading mods.
• OutOfMemoryError appears in the crash report.
• Lag spikes line up with garbage-collection messages in the console.
• Memory use stays close to the limit even with only a few players online.

How to make a modpack use less memory

• Pre-generate the world with a mod such as Chunky so new chunks aren't generated while people play.
• Lower simulation-distance to 6–8. Machines and farms only run in simulated chunks.
• Limit chunk loaders to what players actually need.
• Add performance mods if the pack doesn't include them. On Fabric, Lithium and FerriteCore reduce CPU and memory use; ModernFix helps on both Fabric and Forge.
• Remove mods no one uses. Every mod costs memory whether or not anyone uses its content.

Which Beacon plan fits a modded server?

Beacon servers run on AMD Ryzen 9 7950X3D processors with NVMe storage, which suits modded Minecraft's single-thread and chunk-loading load. Modpacks can be installed from the panel. See every plan's specs and current price on the facts page, or read How Much RAM Does a Minecraft Server Need? for vanilla and plugin servers.