Fact · Speech recognition
51177times faster than real time
In our October 2026 benchmark on a Mac with an M2 Pro, Apple SpeechTranscriber transcribed 100 Portuguese FLEURS recordings about 51177 times faster than real time.
Measured by us on October 19, 2026, from 100 recordings
Our own measurement
This number comes from our benchmark, not from another publication. The full record (the setup, every recording's checksum, every transcript and timing) is published, so you can recompute it.
- What it measures
- Apple's on-device speech model in macOS 26 (SpeechAnalyzer with a SpeechTranscriber module, transcription preset), with the locale given (en-US, de-DE, fr-FR, es-MX, it-IT, pt-BR). Run on macOS 26.6.2, 16 GB of memory; other apps were open, as on any working Mac.
- How it is measured
- Speed = 1,284.5 seconds of audio / 0.03 seconds of processing = 51176.9 times real time, over 100 recordings processed one at a time on a warm engine.
- What it does not show
- Speed depends on the chip, memory and what else the Mac is doing, and short sentences carry a fixed overhead per recording, so long recordings run faster than this.
In the data
A row of Speech Recognition Speed: Real-Time Factor Data, as Apple SpeechTranscriber, Portuguese (M2 Pro): 51,177 times faster than real time.
- System
- Apple SpeechTranscriber
- Kind
- Built-in dictation
- Hardware
- Apple M2 Pro
- Test set
- FLEURS
- Year
- 2026