CoreGuardthe silent SSD write storm
dangerous — and silentNo heat. No fan noise. Nothing sounds wrong — and a runaway sync helper is quietly writing hundreds of gigabytes to your SSD, spending endurance you can't see. This is the incident type that hides from your senses.
a runaway sync helper · quiet, cool — and burning endurance · ~2 h compressed
cpu temperature · full recording
- 13:16observeda sync helper starts hammering the SSD with writes
- 13:32observedfans barely move, temps stay cool — nothing SOUNDS wrong
- 13:48alertCoreGuard write-anomaly warning: cloudsyncd (example) wrote ~200 GB in about half an hour — far above its usual rate
- 14:08interpretedsilent endurance burn: no heat, no noise — only the write counters see it happening
- 14:34observedthe storm ends — roughly 480 GB written, about +0.1% of rated endurance in one afternoon
- 14:52interpretedthe (Pro) per-app write timeline keeps the whole afternoon on record, and the years-left estimate adjusts. The warning itself? Always free.
CoreGuard write-anomaly warning: cloudsyncd (example) wrote ~200 GB in about half an hour — far above its usual rate
Drag the slider to replay the whole incident. Every value here is a recorded, hand-authored example — not telemetry from a real Mac.
Recorded timeline — 13:16 a sync helper starts hammering the SSD with writes · 13:32 fans barely move, temps stay cool — nothing SOUNDS wrong · 13:48 CoreGuard write-anomaly warning: cloudsyncd (example) wrote ~200 GB in about half an hour — far above its usual rate · 14:08 silent endurance burn: no heat, no noise — only the write counters see it happening · 14:34 the storm ends — roughly 480 GB written, about +0.1% of rated endurance in one afternoon · 14:52 the (Pro) per-app write timeline keeps the whole afternoon on record, and the years-left estimate adjusts. The warning itself? Always free.
1 What you'd observe
A sync helper starts hammering the SSD with writes. The fans barely move; temperatures stay cool. Nothing sounds wrong — and that's the trap. The one instrument that sees it is the write counter, which climbs while heat and noise stay flat.
2 What it means
This is silent endurance burn. SSD wear tracks total bytes written (TBW), and it's invisible to the things people watch — free space and file size don't move, because the writes are churn, not growth. CoreGuard's write-anomaly warning flags that the helper wrote far above its usual rate — ~200 GB in about half an hour. That danger-visibility is free: you don't need Pro to be warned something's wrong.
3 How it resolves
The storm ended at roughly 480 GB written — about +0.1% of the drive's rated endurance in a single afternoon. Once is nothing; every day would matter. The Pro per-app write timeline keeps the whole afternoon on record and the years-left estimate adjusts — but the warning itself is always free, because the dangerous incidents are the ones you can't hear.
The full dataset. Every reading in this recorder — temperatures, fan RPM, the process series, and the event log — as one sanitized JSON file. It's a hand-authored example, not telemetry; reuse it freely.
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