1–2 FPS overhead · 80 MB RAM
Performance &
FPS impact
What ASR actually costs you in frames, the optimisation mods we recommend pairing it with, and how to read the in-game profiler if something feels off.
On a mid-range rig (RTX 3060 / Ryzen 5 5600X / 16 GB RAM) ASR adds 1–2 FPS of overhead in dungeons and
less than 1 FPS at the Garden. Most "ASR is laggy" reports turn out to be Iris + Sodium version mismatch
or insufficient heap.
Measured benchmarks
Average of three 10-minute runs each, 1080p, Sodium 0.6.2, Iris 1.8.5, vanilla shaders off, no other mods. Higher is better.
| Scene | No mods | ASR only | ASR + Sodium | ASR + Skyblocker + Sodium |
|---|---|---|---|---|
| Hub idle (16 chunks) | 192 | 189 | 312 | 308 |
| Dungeon F7 boss room | 118 | 116 | 205 | 198 |
| Crystal Nucleus | 104 | 102 | 178 | 173 |
| Garden (planted, 64 plots) | 89 | 87 | 156 | 151 |
| Kuudra t5 phase 3 | 76 | 74 | 138 | 133 |
RAM
- Resident set size adds ~80 MB on top of vanilla once HUD is initialised
- No native memory allocations — pure Java
- Garbage-collection pauses indistinguishable from vanilla under G1GC
Recommended companion mods
- Sodium — rendering rewrite, 80–100% FPS gain. Mandatory.
- Iris — only if you run shaders; otherwise skip.
- Lithium — server-tick optimisations, ~5% TPS smoothing.
- FerriteCore — cuts heap usage 30%+ via deduplicated block states.
- Indium — needed if you run Sodium with other rendering mods.
If your FPS tanks
- Open F3, take the TPS / FPS reading.
- Toggle ASR off with
/asr disable; retake the reading. - If the delta is >5 FPS, attach
latest.log+ GPU/CPU + scene to a GitHub issue. - If the delta is <2 FPS, the issue is elsewhere — usually a Sodium / Iris mismatch.