Performance Difference Between wasmer run python/python (Registry) and wasmer run python-v0.2.0.wasmer (Local File)

[hemantapkh]

Hi,

I’m new to Wasmer and experimenting with running Python wasmer package. I’ve noticed a significant performance difference between running a package from the registry (wasmer run python/python) and running the same package downloaded locally (wasmer run python-v0.2.0.wasmer). I’d appreciate your help in understanding the cause of this discrepancy.

1. Registry-based execution

time wasmer run python/python -- -c "print('hello world')"

hello world
wasmer run python/python -- -c "print('hello world')"  0.06s user 0.05s system 94% cpu 0.117 total

The first execution of this takes longer due to downloading the package, but subsequent runs are quite fast, taking around ~110ms.

2. Local file execution

I downloaded the python-v0.2.0.wasmer from wasmer.io and ran

time wasmer run python-v0.2.0.wasmer -- -c "print('hello world')"

hello world
wasmer run python-v0.2.0.wasmer -- -c "print('hello world')"  0.41s user 0.12s system 87% cpu 0.609 total

This takes approximately 500-600ms, with most of the time spent on "Resolving dependencies."

This is consistently 4-5x slower than running (wasmer run python/python). I expected similar performance since both should be running the same thing. My goal is to use the local file to avoid periodic re-downloads, as it occasionally says "looking up python/python," which slows down execution.

Thank you!