嵐 /aɾaɕi/ (arashi) — Japanese
n. storm; tempest.
What is arashiOS?
arashiOS builds on Asahi Linux and ALARM (Arch Linux ARM). On top of that foundation, it adds CachyOS-inspired optimizations and additional ARM-specific tuning — purpose-built for Apple Silicon.
The result: A snappy and delightful daily-driver Linux desktop tuned specifically for your hardware, with gaming and battery optimizations in mind.
No compromises. No generics.
More details coming soon.
Benchmarks: arashiOS vs Stock Asahi + ALARM
Real numbers. Same hardware. No cherry-picking.
NVMe I/O
┌───────────────┬──────────────┬──────────────┬──────────────┐
│ Test │ Stock │ Arashi │ Improvement │
├───────────────┼──────────────┼──────────────┼──────────────┤
│ Seq Write │ 1,982 MiB/s │ 2,592 MiB/s │ 30.8% faster │
├───────────────┼──────────────┼──────────────┼──────────────┤
│ Seq Read │ 2,439 MiB/s │ 2,563 MiB/s │ 5.1% faster │
├───────────────┼──────────────┼──────────────┼──────────────┤
│ Rand Read 4K │ 186,527 IOPS │ 223,272 IOPS │ 19.7% faster │
├───────────────┼──────────────┼──────────────┼──────────────┤
│ Rand Write 4K │ 36,057 IOPS │ 33,151 IOPS │ 8.1% slower* │
└───────────────┴──────────────┴──────────────┴──────────────┘
*Random write variance is high on Arashi (41K → 27K → 31K across runs). Probably due to BTRFS CoW/journal interaction, not a real regression. Stock kernel was very consistent (35.6K–36.4K).
Summary:
- 30% faster sequential writes — that’s massive
- 20% faster random reads — huge for app launch, file browsing
- 5% faster sequential reads
Complete A/B Results
┌─────────────────────────┬─────────────┬─────────────┬───────────────────┐
│ Metric │ Stock │ Arashi │ Improvement │
├─────────────────────────┼─────────────┼─────────────┼───────────────────┤
│ Scheduler latency (p99) │ 4,037 us │ 161 us │ 96% faster │
├─────────────────────────┼─────────────┼─────────────┼───────────────────┤
│ NVMe seq write │ 1,982 MiB/s │ 2,592 MiB/s │ 30.8% faster │
├─────────────────────────┼─────────────┼─────────────┼───────────────────┤
│ NVMe rand read │ 186K IOPS │ 223K IOPS │ 19.7% faster │
├─────────────────────────┼─────────────┼─────────────┼───────────────────┤
│ Hackbench pipe │ 7.31s │ 6.02s │ 17.6% faster │
├─────────────────────────┼─────────────┼─────────────┼───────────────────┤
│ Hackbench socket │ 14.14s │ 11.84s │ 16.3% faster │
├─────────────────────────┼─────────────┼─────────────┼───────────────────┤
│ Idle power │ 24.55W │ 22.36W │ 2.2W saved (8.9%) │
├─────────────────────────┼─────────────┼─────────────┼───────────────────┤
│ GPU (glmark2) │ 3,003 │ 3,254 │ 8.4% faster │
├─────────────────────────┼─────────────┼─────────────┼───────────────────┤
│ Boot time │ 6.36s │ 5.81s │ 8.6% faster │
├─────────────────────────┼─────────────┼─────────────┼───────────────────┤
│ NVMe seq read │ 2,439 MiB/s │ 2,563 MiB/s │ 5.1% faster │
├─────────────────────────┼─────────────┼─────────────┼───────────────────┤
│ E-core latency │ 23 us │ 12 us │ 47.8% faster │
└─────────────────────────┴─────────────┴─────────────┴───────────────────┘
No performance regressions. All gains, no significant tradeoffs.
What this means day-to-day
- No UI jank under load — 96% less scheduler latency
- Faster app launches, package installs, git ops — 20-31% faster disk I/O
- Longer battery life — 2.2W less idle draw
- Smoother compositing and video — 8% GPU gain
- Better multitasking — 17% faster inter-process communication