The Killd Board / Withers
How many withers does it take to crash a Minecraft server?
3,459 before the tick rate gave way, and 17,934 before the server died. The interesting part is the comparison: the ender dragon managed the same damage with 605. Both are bosses, and one of them is nearly six times more expensive than the other.
Paper 1.21.11 · AMD Ryzen 7 9700X · 6GB allocated
Why withers cost so much
A wither hovers rather than flying a route, and that turns out to matter enormously. It tracks targets with three heads, fires wither skulls that are projectile entities in their own right, and breaks blocks wherever those skulls land. That is a lot of work, and it still costs a fraction of what the dragon costs, because the dragon adds true flight navigation through open space, a multi-part hitbox and a phase system on top of all of it. Boss is not a performance category. What the mob actually does each tick is.
How we tested it
Everything spawned into a single chunk, in one pile, with the server left running until the tick rate gave up. The server ran Paper 1.21.11 on an AMD Ryzen 7 9700X with 6GB allocated, which is the same hardware and the same RAM policy as an ordinary Hostd plan. We watched TPS and tick times rather than guessing, wrote down the count where the server first fell behind, and kept spawning until it either died or made it clear it was not going to.
Modded packs are full of custom bosses. This is the run that says you cannot judge one by its health bar: measure it, or watch your tick times while it is loaded.
What this means for your server
If your own server is printing Can't keep up! Is the server overloaded? the cause is the same shape as this one: something in the tick loop is taking longer than its 50ms budget. Roastd reads your RAM allocation, view distance, player slots, JVM flags and logs and names which of those it is. No account, no world upload, no charge.
Questions about withers
Do withers lag a Minecraft server?
A wither fight does, briefly, and more than most mobs. It fires projectile entities continuously and breaks blocks where they land, so the tick cost spikes for as long as it is alive. It took 3,459 in one chunk to push our test server under 20 TPS, which puts it mid-board: expensive for a mob, cheap for a boss.
Which is worse for a server, a wither or an ender dragon?
The dragon, by a wide margin. It broke our server at 605 against the wither at 3,459. The dragon flies a real path through open space, has a multi-part hitbox and runs a phase system that spawns further entities. The wither mostly hovers and shoots.
Elsewhere on the board
Keep reading
Rent the machine we keep breaking
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