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sitespeedio / sitespeed.io

sitespeed.io is an open-source tool for comprehensive web performance analysis, enabling you to test, monitor, and optimize your website’s speed using real browsers in various environments.
https://www.sitespeed.io/
MIT License
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The TBT metric value is relatively high in the sitespeed test results. #4311

Open heavenmyth opened 1 week ago

heavenmyth commented 1 week ago

Your question

The TBT metric value is relatively high in the sitespeed test results.

When using Lighthouse, the TBT is around 200ms, but in the sitespeed test, the TBT is around 600ms.

soulgalore commented 1 week ago

Hi @heavenmyth TBT depends on the CPU speed on the server where you run the tests. Do you run both tests on an isolated server or do they run on different machines? Do you set the CPU speed on the machine when you run the tests?

heavenmyth commented 1 week ago

HI @soulgalore ，Thank you for your response I conducted the tests on the same Mac computer, which has an Intel chip. The difference is that Sitespeed was run using a Docker image, while Lighthouse was run directly in the browser.

The Docker command executed is: docker run -e MAX_OLD_SPACE_SIZE=4096 --shm-size=4g --rm -v "$(pwd):/sitespeed.io" sitespeedio/sitespeed.io:35.3.1-plus1 urls.txt -b chrome --config config.json

soulgalore commented 5 days ago

Yeah Docker adds some overhead.