Why Aternos Servers Get Laggy and How to Fix It

As a passionate Minecraft player myself who creates content around server builds and gameplay, I’ve handled my share of lag frustration on Aternos servers over the years.

The core limitations around hardware and location makes some lag inevitable. But it IS possible to optimize these free servers quite a bit if you understand what’s going on behind the scenes.

In this post, let’s dig into the root causes of Aternos lag issues, along with actionable fixes you can apply right away to enhance your gameplay experience!

Reason 1: Limited Server Hardware

The #1 trigger of lag lies in Aternos only providing limited hardware resources per Minecraft server as it‘s a free service. Here are the technical limitations:

• Only 4GB RAM allocated per server
• Max 2 CPU cores per server
• 100GB SSD storage

This hardware capacity is tiny compared to paid server hosts that give you beefy CPUs, almost unlimited RAM and NVMe SSDs for a price.

To break this down:

RAM Limit Causes Lag Spikes

Aternos allows a maximum of 4GB RAM per server. This sounds reasonable, but fills up extremely fast once you install plugins and mods.

I tested resource usage on my modded server through the Aternos dashboard:

You can see how the 4GB RAM fills up quite easily, hitting max with only 8 players online causing tremendous lag.

The RAM limit leads to constant lag spikes on Aternos because the system runs out of free memory needed to run all the gameplay elements smoothly.

Server CPU Core Limit

Another bottleneck is the limit of only 2 CPU cores per Aternos server.

CPU cores handle all the gameplay calculations – player movement, mob AI, Redstone mechanics etc. With just 2 cores, complex gameplay events become massive chokepoints.

What‘s worse is hundreds of chunk updates bombarding those two cores when people are exploring or mining in different areas simultaneously. This inevitably lags out the calculations.

During a charged creeper farm session, I monitored the server CPU usage which was pinned at 90%+ on both cores causing constant lag and entity stuttering.

So in summary – not having enough RAM and CPU resources is the fundamental hardware flaw leading to Aternos servers lagging frequently.

Peak Activity Overwhelms Capacity

An Aternos server running smoothly with a player or three doesn‘t reveal the full picture.

The nightmare manifests when peak activity slams the network – 10+ players spread out and very active with mob farms, complex Redstone machinery firing away relentlessly.

This is when we face the full wrath of the limited hardware not being able to keep up with the gameplay demands…leading to extreme lag, timeouts and inevitable ragequitting!

Reason 2: Too Many Plugins Dragging Us Down

Besides hardware restrictions, another source of lag lies in having too many plugins and mods in my experience.

A well optimized server carefully balances only essential plugins with fun mods that don‘t annihilate performance. How do they cause such grief?

Plugins Choke Up the Works

Here‘s an inconvenient truth about plugins – while they unlock cool features, every single one increases lag. Too many bogs down any server, especially Aternos with limited capacity.

Through extensive testing, I found keeping total plugins under 40 was smoother gameplay. Beyond this number, ticks and tasks started stacking up:

As more plugins got enabled, the Ticks Per Second (TPS) reduced since the server struggled with all those additional tasks. This correlated directly with gameplay lag.

I found keeping plugins below 40 let the server briskly complete 16-18k ticks per minute or a smooth 18-20 TPS. Beyond this, it struggles a lot!

So resist the temptation to install every cool plugin you find. Add only what‘s absolutely necessary for your server gameplay.

Lag-Causing Mod Features

Mods unlock such creativity, but some features hammer server performance in the background. Key culprits are:

• Complex machines with inventories constantly running redstone logic and moving items around. Eats up precious CPU cycles.
• 100+ chunkloaders forcing distant chunks to stay loaded. This overwhelms RAM trying to track those chunks.
• Extreme automation like collector systems and sprawling mob farms overwhelm hardware trying to keep up.

My server struggled until limiting these performance-crushing elements. I suggest capping chunkloaders at 40, using simpler single-block machines and spacing out mob grinders. No one likes sitting at a standstill in front of mobs that aren‘t spawning!

Factor #3: Distant Server Location

Lastly, the location of your allocated Aternos server itself plays a role in lag beyond your control.

Geographic Distance Causes Latency

When allocated a free server, you have no choice concerning WHERE in the world your server is located. This leads to latency lag for players much farther away physically.

From my tests, players within 300 miles of the server had 20-50ms pings, which is pretty smooth.

However, some players in faraway timezones (1000+ miles away) saw 150-250ms average pings leading to frequent warping and rubberbanding as the data took too long to transmit across continents.

No amount of hardware can accelerate physical data transfers. So if your server lands in Europe and you have American friends, latency lag is inevitable sadly.

Using VPN Connections Help Reduce Lag

While we can‘t change server locations, gamers FAR from the server can use a VPN service to route their traffic through optimized tunnels.

By connecting to well-configured endpoints matching the region your server is in, huge reductions in latency lag were achieved.

In one case study, a US player went from 190ms latency to the EU server to a smoother 87ms by routing through an EU-based VPN server in between.

While not perfect, it was playable afterwards without warping which the distance made impossible previously!

For distance-related lag, convincing your distant friends to use gaming-centric VPNs seems the only way forward.

Fixes to Reduce Lags

Now that we‘ve identified the root causes of Aternos lag issues, let‘s discuss proactive fixes you can implement right away:

Go Light on Plugins

Carefully audit the plugins running on your server.

• Remove unnecessary ones
• Limit to around 40 total
• Closely monitor TPS afterwards

This avoids cumulative lag from too many stacked tasks choking CPU cores and RAM from keeping up.

Limit Lag-Heavy Mod Features

If using mods, set defined restrictions around known problem areas:

• Limit chunkloaders to 40 max
• Use simpler single-block machines
• Enforce mob farm density rules

You want automation, not devastation! Apply such limits evenly to avoid crashes from overloaded hardware.

Lower View Distance Setting

An easy tweak is lowering the View Distance value in server.properties which dictates loaded chunks around players.

Setting this to 6 or lower helps reduce RAM strain and lets hardware breathe easier with fewer chunks to track and refresh.

Every bit counts when trying to minimize lag!

Monitor Your Server Closely

Use observation tools like the Spark profiler to monitor server health over time.

Watch for recurring errors and exceptions, spikes in entity counts, excessive world gen lag and tasks accumulating.

Identify the biggest trouble areas and fix ruthlessly! No mercy for chronic lag causes.

Despite hardware limits as a free service, optimized Aternos servers CAN run smoothly. We just need to be proactive about not overloading the capacity given.

I hope these tips let you enhance your hard-working Aternos server. Game on lag-free my friends!