Why is my server overloaded, and how do I fix it (CPU, RAM, RAM Buffer)?
"Overloaded" means your server can't keep up with the work it's being asked to do — usually CPU-bound ticks or memory pressure. The good news is that most overload is fixable with sensible RAM settings and a bit of load trimming, all from the Startup tab and your configs.
What overload actually is
When you see "Can't keep up!" repeatedly, the server is falling behind on its tick loop. That's driven by CPU load (single-thread speed matters most) or by running low on memory.
Fixing overload
- In the Startup tab, set RAM sensibly: your minimum (Xms) must never exceed your maximum (Xmx), or the server crashes instantly.
- Set a RAM Buffer to prevent out-of-memory crashes — roughly 300–500MB under 3GB, and 1000–3000MB for 3–10GB+.
- Reduce load: lower view/simulation distance, cut entity/mob counts, and remove heavy plugins/mods.
- If it's a constant ceiling despite tuning, upgrade to more RAM/CPU.
Warning: Setting the minimum RAM higher than the maximum will crash the server on startup — always keep Xms ≤ Xmx.
Tips & best practices
- Aikar/G1GC flags help on Minecraft 1.8–1.18 (Forge 1.8–1.16.5), and the panel applies these for you automatically.
Frequently asked questions
I get "Can't keep up!" constantly — what is that? That's overload. Tune the settings above, trim load, or upgrade if you've hit a genuine ceiling.
Is more RAM always the fix? Often not — CPU single-thread speed is the real limit for heavy modpacks and redstone. Our Supreme/Ultimate (Ryzen) tiers help most there.