Every run with CoreML "first run on a device may take a while ..."

[tarasis]

I'm on macOS 14.4.1, and testing out whisper.cpp.

I have compiled binaries with both CoreML and just Metal.

But every single time I run the CoreML version it spends an age loading the coreml model version, and doesn't seem to cache for the next run

whisper_init_state: loading Core ML model from 'models/ggml-small.en-encoder.mlmodelc'
whisper_init_state: first run on a device may take a while ...

Runs 1-3 with command

./main -m models/ggml-small.en.bin -f samples/jfk.wav

whisper_print_timings:    total time = 25367.44 ms
whisper_print_timings:    total time = 25146.03 ms
whisper_print_timings:    total time = 25412.08 ms

Not sure what I'm doing wrong, but I was expecting it to cache whatever it was doing so subsequent runs were quicker.

[FrostiizGit]

I'm playing with whisper.cpp today and was impressed by the result so I wanted to compare the large model and the large one using CoreML.
I'm on MacOS 14.4.1 (M1 Max) and every time I run my command it says first run, maybe I did something wrong so I'll write the whole process I followed:

1 - ./models/generate-coreml-model.sh large-v3 To generate the coreml model
2 - make large-v3 WHISPER_COREML=1 make -j To build whisper with the coreml support
3 - ./main -m models/ggml-large-v3.bin -f ./samples/myaudio.wav The command used to run the model on my audio

I tried the same command 5 times in a row and every time I had the first time message appear:

whisper_init_state: loading Core ML model from 'models/ggml-large-v3-encoder.mlmodelc'
whisper_init_state: first run on a device may take a while ...

Here are the results:

1 --> whisper_print_timings:    total time = 124125.69 ms
2 --> whisper_print_timings:    total time = 123887.73 ms
3 --> whisper_print_timings:    total time = 123487.95 ms
4 --> whisper_print_timings:    total time = 123119.12 ms
5 --> whisper_print_timings:    total time = 123199.10 ms

Example of full timings for one of the run:
whisper_print_timings:     load time =  1048.37 ms
whisper_print_timings:     fallbacks =   0 p /   0 h
whisper_print_timings:      mel time =     9.26 ms
whisper_print_timings:   sample time =    52.25 ms /   180 runs (    0.29 ms per run)
whisper_print_timings:   encode time =  1486.21 ms /     1 runs ( 1486.21 ms per run)
whisper_print_timings:   decode time =     0.00 ms /     1 runs (    0.00 ms per run)
whisper_print_timings:   batchd time =  1431.58 ms /   178 runs (    8.04 ms per run)
whisper_print_timings:   prompt time =     0.00 ms /     1 runs (    0.00 ms per run)
whisper_print_timings:    total time = 123199.10 ms

Maybe this is the correct behaviour and thus using the coreML version is not worth it on small samples or I'm simply doing something wrong.

[ceberhardt]

I'm on macOS 14.2.1 and I've run into the same problem.

[ggerganov]

I'm on 14.4.1 and don't observe this issue - first time is slow, but next runs load fast

[ggerganov]

The Metal backend was incorrectly initialized 2 times, which I support might have caused this problem. Should be fixed on latest master after #2152 was just merged

[furyhawk]

M1 pro. os14.4.1. latest master pull and make with coreml:

• base.en 1st run whisper_print_timings: total time = 9904.61 ms -> 2nd run whisper_print_timings: total time = 462.63 ms. 👍

• small.en 1,2,3 run no improvement ~ whisper_print_timings: total time = 24493.98 ms 🤷

--edit tried on macos 14.5 too.